Will's books

Will's books


Friday, June 20, 2014


Roof Design - Framing Consulting
Architects: I may be able to help resolve some design issues you are struggling with by offering a second opinion or presenting some new options. I can also give my opinion on the degree of difficulty a builder may have with a particular design and how it might be simplified.
Builders: I can calculate a job's tall wall and rake wall heights, develop a roof rafter cut list and/or design a stacking system progression. If needed, I can come on site to help direct your crew with a difficult project including helping cut the roof rafters, guiding the stacking process or building tricky stairways.  I speak Spanish if required.
Anybody: I am available to teach workshops/classes, give seminars or tutor privately on roof framing.

Roof framing seminars or private tutoring
I am available to teach workshops/classes, give seminars or tutor privately on roof framing.

Production Roof Rafter Cutting Service
If you will be building a "cut & stack" housing tract (as opposed to installing roof trusses) and are looking for a roof cutter - contact us. We have the tools and techniques to help you save time and money.

Tree House Design & Construction
If you have the dream to build a place up in the trees for the kids, a deck amongst the branches to enjoy a special view and observe wildlife or a simple hideaway where one can escape the hustle bustle to meditate in silence.
Contact us, we would enjoy working with you to fulfill that dream. Click HERE for a fun video of  a sample job.

 Contact Will Holladay at whframingconsultant@gmail.com

Satisfied customer                                                 

Hello Will,

The pool pavilion interior finishes are on hold pending spring weather.  I'll tell you more later with pictures.  We absolutely could not have done the complicated roof framing without your direction and detailed information.

I'll be sending you drawings for a substantial project in the future.  I hope you'll
be interested in working out the roof framing details.

Thank you.
Best Regards,
Norristown, PA

Thursday, March 13, 2014


To help carpenters and builders cut their roof rafters quicker and more accurate we are striving to make available through this website: 1 cutting guide tool and 2 saw base kits.


*** We need a fabricating partner for the various kits.  If you are interested please contact us.


An order link should be set up as soon as we have a consistent supply available.


CONTACT ME FOR MORE INFO whframingconsultant@gmail.com



 The Roof Cutter's Birdsmouth Cutting Guide Tool  This hand held guide allows folks who hand cut their 2x common rafters with a regular wormdrive circular saw, to make the birdsmouth's seat-cut quickly without the need to mark or follow a cut-line.   This guide tool also automatically accomplishes the difficult task of transferring the common rafter heel-stand correctly to the hip/valley rafter.  The unit is fully adjustable between 4/12 - 12/12 roof pitch for both common and hip/valley rafters.  It can be used with 2x8, 2x10, and 2x12 material.

Cutting demo video click HERE. 

Guide setup instruction video click HERE.






 The Roof Cutter's Swing Table saw base kit   This kit installs on a standard Skil model 77 or 5860 wormdrive circular saw.  It allows these saws to swing well past the standard 45 degree limit and make the very shallow angled seat-cut pass during the production gang-style cutting of common and hip jack rafter birdsmouths.  For a video on how to assemble and install the kit on your Skilsaw click HERE.

kit assembled


kit installed









NOW AVAILABLE from Nick Ridge. 


Click HERE for more info and to purchase. 



 The Roof Cutter's Ridge/Seat chainsaw saw base kit  This kit allows installation of either a large powerful chainsaw for the gang-style cutting of common rafter ridge cuts or a smaller tree limbing chainsaw for the gang-style cutting of common and hip jack rafter birdsmouth seat-cuts.

 small chainsaw mounted for seat cut application
kit assembled


















Monday, March 10, 2014

Secret places above - building in the trees

"Knowledge is wonderful but imagination is even better."
— Albert Einstein

A home in the trees for 4 young brothers

Nearly every rough carpenter I know built a tree fort when they were kids. It's just in the blood. I remember well the one my brother Joel and I built when we were 11 and 12 yrs. old. Even at that young age we already had a fair amount of carpentry experience. It fell upon us “men” of the family to upkeep the small farm where we grew up. Between the two of us we built horse corrals, sheds, chicken/rabbit/pheasant coops, and any other structure that may have been required. We also made time to invent secret places. One such place was our tree fort that was totally invisible to the outside world. From there we could defend our ranch with great effectiveness against the raiding marauders of Lomita CA just down the hill (or escape from our sisters). Other than just farm boy ingenuity, I have no idea how we came up with the tree fort design. 50 yrs ago there was no Internet of course so our “go to” resource was the infamous Encyclopedia Britannica. It was heavily relied on for homework assignments so it could well have been that we copped an idea from there or maybe our incentive came from a Tom Sawyer novel. In any case, without building department approval (not even sure if that gov. welfare job had been invented yet) and under the cover of darkness we constructed our masterpiece. We could not risk drawing enemy attention to our project. Not only was this long before the Internet but thankfully this was also long before spy satellites. Otherwise, we would have had to coordinate our building efforts for when these devices were over the horizon and blind. As it was, in those days we only had to worry about a stray U2 that may have confused Los Angeles with Moscow. That was an acceptable risk knowing the U2 was based out of England and would run out of fuel a long ways before reaching Southern CA. (Photo 1)

Photo 1 - U2

In our personal Sherlock forest we found two straight trees that were situated about 12 feet apart having a trunk size of about 8”-10” diameter. I can’t remember the tree species but they were green. At 8’ above the ground and spanning from tree to tree we attached a 2x8 to each side of the trunk using lag bolts. In effect we had sandwiched the two trees. The two 2x8s were run level from side-to-side and from end-to-end. On top of these we framed a 4’x 12’ floor using 2x4 joists at +/-24” OC and sheathed it with scrap pieces of plywood. At each end of the floor section we ran a pair of knee braces down to the tree trunk at 45 degrees to keep the deck from rocking. (Fig. 1) We didn’t fret much about a handrail as we shaped and wove the tree branches to create a perimeter. To get up to the fort you either scaled one of the support trees or climbed a rope that was hung appropriately. We didn’t want to make it too easy for the enemy to invade.

Fast-forward some 50 yrs to the year 2009, and we once again catch up with one of those 2 young brothers. He now limps around a bit, being an old, well abused rough framer who is many decades past his prime. But for some strange reason this brother never outgrew dreams of building tree houses. On the highest shelf of his sparse little “office” there are half a dozen dusty books on the subject that get pulled down now and then to be looked over on a rainy day. If you haven't already figured it out - that poor soul is I.

Times certainly have changed since those early days. There is now a myriad of spy satellites in the sky so advanced that they can read the words off a newspaper just about anywhere in the populated world. Be hard to build a tree house undiscovered nowadays.  Even your communications are at risk since the feds have drones that fly around and suck data off your cell phone. Yep cell phones - you heard me right. No more land lines - and that wonderful sounding ching-ching-ching of the rotary dial telephone. Hard to believe what has happened in that young man's lifetime. Man has been to the moon and he even keeps an “outer space house” where he can escape from the wife for a break if needed. That is why it is up there isn’t it?   (Photo 2)
Photo 2 - space station

I have been blessed to be a part of many extravagant building projects during my career but I can never seem to dash the longing to design and build a Swiss Family Robinson style tree house. I have so many cool ideas to try out (they are secrets).  I hope I get the opportunity before I hit the grave. I have seen many articles/videos/etc on tree houses (ie: Treehouse Masters, etc) but I would have to say that many do not meet my definition of a real “tree house”, which states “that the structure must be totally supported by the tree itself - no posts or braces to the ground”. (Photo 3) To use the ground as support is definitely cheating and bad ju -ju. Only a set of stairs to access the tree house is allowed to touch the ground. And that is only as a concession for old disabled folks like me who can no longer shimmy up a climbing rope or rope ladder. Building a house on stilts in amongst the trees so their branches appear as porch plants does not constitute a tree house. 

Photo 3 - a REAL tree house

Needless to say, I was utterly delighted when the wife of a dear friend called to ask if I would build a tree house for their 4 young boys. Having seen my design work and construction on various other specialty projects she gave me free range to do as I pleased within a set budget. So without another word, I jumped in my old truck and went snooping around their property to find a tree that I could use. Unfortunately, I discovered that all the available trees were relatively young Eucalyptus (10” diameter). These certainly couldn't support a tree house of any real size so I came up with the idea to build two smaller tree mounted structures and connect them using a cable car. Something fun for the boys to do. One structure would be an enclosed tree house (ETH) with 4 beds for overnight stays while the other would be an open viewing platform with bench seats (VP). Both would have incredible views of the nearby volcano. A stairway would provide access to the ETH while the VP could either be accessed by the cable car or a climbing rope. After getting approval for this plan from the owner, I began formulating a strategy of how best to accomplish the construction. Since it was a small job and I would be inventing on the fly, I decided to build the project solo.
Tree house construction has no real standard methodology. One must invent a special support system to fit each tree’s unique form in light of the local weather conditions. The home site where I would build these two tree structures faces 6 months of monsoon rains followed by 3 months of strong winds each year so I would need to use very durable materials and keep the tree house’s wind profile small. A tree house may seem innocent enough but in strong winds it acts like a giant sail that can easily overload the root system’s ability to resist the flexing load and down goes the tree. Give it a few years and the tree should upgrade its root system somewhat to help counterbalance the new added load. The structural design in this case would also need to allow for plenty of tree trunk movement otherwise the constant wind generated movement would just jiggle everything apart in no time.

I chose to put the ETH into a Eucalyptus tree that divided into 2 separate trucks about 5 feet above the ground while the VP would be installed in a fairly straight Eucalyptus tree about 100’ away. I determined to set the ETH floor about 12’ above the ground. This was as high as I could place the structure so that its roof was just below where the trunks flowered out into a myriad of fingers. The VP’s height would match the ETH at a position exactly horizontally level. This would facilitate travel by cable car between the 2 tree structures.

One consideration a tree house builder must have when building a tree house is to make effort to protect the tree’s health. The fewer penetrations into the trunk the less likely it is to hurt the tree. The last thing you want is for the tree to die and all your hard work be for neigh. After some brainstorming, I devised a method where I would attach the ETH to the tree itself using only 3 “through-the-tree” fasteners while the viewing platform I would attach to the tree with (4)- 4” long lag bolts at two different levels. Every penetration into the trunk would be well sealed using spray car undercoating. This would go a long way to protect the tree from bug and disease infiltration.

My first problem was to devise a good way to work up high in the tree with ease. My experience as a roof stacker had prepared me well for this challenge since I was always inventing ways to get up high and frame various parts of complicated roofs. I detest working from ladders therefore I quickly devised a simple platform type scaffold built around the tree itself. Upon it I would assemble the complete floor joist system and connect it to the tree. This scaffold method would work well for both tree structures even though they had different systems of support. (Fig. 2) To start, I framed two moment frame units laid flat on the ground using (2) 2x4 verticals and a 2x6 horizontal for each of the two trees where the tree structures were to be built. I set the height of the horizontal member so the top surface of the scaffold planks when in place would match the bottom of the platform's floor joists (FJ). I also adjusted the leg lengths to conform to the unevenness of the terrain so that when the moment frames were stood they would create a level working plane. The moment frames were X-braced while laid flat and then stood on opposing sides of the tree. Foot long flat 2x6 blocks were placed under each leg to keep them from sinking into the ground when it rained. After these moment frames were braced plumb using some temporary angle braces to the ground, I connected the two units at the scaffold level on each end using a pair of 2x4 horizontal cross ties that spanned between the vertical legs and then X-braced the assembly on these two connecting sides. I also drove a stake into the ground at each leg and connected it to the 2x4 vertical leg. I next fastened 2x4 horizontal corner ties at the scaffold level on two opposing corners for extra rigidity (Roof Cutter's Secrets pg. 37). Finally, I tossed up some long 2x12s planks that spanned between the two cross ties and on top of them I tossed up 2 more planks that went the opposite direction. The scaffold platform looked somewhat like the number (#) symbol when viewed from above. I made the moment frame support structure wide enough so that I could easily slide the planks out to use outside the building structure when it came time to install the exterior siding. I feel confident that one could easily use this system of construction up to a height of 20'-22’ above ground level. Above that I have another trick idea that I will save to share some other day.

Fig. 2

With the scaffolds up I began work on the floor structures. Up on the ETH scaffold I mocked up a trial floor system using some 2x4s to see what kind of joist layout would work around the two tree trunks. Since the ETH was to be a 7’x12’ structure (that including a 3.5’ front porch facing a spectacular mountain view), I positioned (2) 2x4s - 12’ (laid flat) on top of the scaffolding simulating the building’s long sides. Perpendicular to and on top of these long boards, I set various 8’ long 2x4s to simulate FJs and moved them around until I achieved a decent layout that would work considering the two tree trunks. I had already determined that the vertical rear tree trunk would pass centered through the enclosed tree house space while the angled front tree truck would pass through the front wall and out the porch. I decided to use two of the joists as “king” members from which the whole tree house structure would get its support. One of these “king joists” (KJ) would be solidly attached to the vertical trunk using a single piece of ¾” all-thread while the other KJ would hang from a the front trunk using two equal length pieces of 3/8” wire cable (imagine using two nylon slings to set a ridge beam with a crane). Since both trunks would move independently, this system allowed that to happen without torquing the structure. I would use Guayacan for all the wood components in the building process except the siding, which would be Spanish cedar. Guayacan is so strong and dense that it actually sinks in water. It is impervious to bugs and weather of any type. I am told you can bury a piece of this wood in the ground and come back some 50 yrs later and find it in the same untouched condition. (link to http://en.wikipedia.org/wiki/Lignum_vitae). The two KJs along with the outside rims on the ETH would be 2x8s with all intermediate joists 2x4s (full dimensional sized lumber). The decking would be 1x4s.


Photo 4
Photo 5
Photo 6
For both structures and throughout the building process I prebuilt as much as I could in sections on the ground near the tree. Sections that were too big to move up in one piece were partially disassembled and reassembled on top of the scaffold. For example: to construct the ETH floor, I bolted all the joists together using ½”machine bolts and brackets fabricated from angle iron (Photo 4 - no Home Depots around here), numbered everything, disassembled it, threw the pieces up on the scaffold, and reassembled it in place. I could have set a winch block up high in the tree and incorporated my trucks winch to lift things but that wasn't necessary.

With the floor structure set solidly on the scaffold, I only had to attach it to the tree trunk. As described previously I through-bolted one of the KJs to the vertical trunk using 3/4” all -thread. About 5' down and directly below this KJ connection I installed a 1.25” diameter 4130 steel pin through the rear trunk to use as the anchor point for the lower ends of two separate diagonal braces made of angle iron. (Photo 5) They reached upward like a “V” and bolted to the KJ, stabilizing it from side-to-side in the level position.

Up on the front trunk I installed a second steel pin of the same size through the trunk about 5' above the KJ. I hung the front KJ from the outside end of this pin while planning to use the inside end of the pin as my anchor for the cable car’s support cable. (Photo 6) To help dampen any side-to-side swinging movement of the front KJ, I ran a wire cable down and back from one end of the front KJ to the lower steel pin at the rear tree trunk. In combination with the staircase coming up from the ground on the opposite end of the KJ it did a good job of stabilizing the hung end of the tree house. (Photos 7, 18)
Photo 7

Photo 8
I prepared the decking on the ground by aligning them flat, side-by-side on stickers. Then I gang-cut them to length, routered a ¼ round on the top edges and predrilled/countersunk for all the decking screws. Once I had the decking laid out on top of the joists, I worked from one end to the other screwing them in place.  Since Guayacan is so hard I had to predrill the joists for the screws as well. Using one electric hand drill set up with a drill bit and a second electric hand drill set up with a screw driver bit I finished the floor deck installation in short order. I used 3/16” x 2.5” Tapcon concrete screws (with a little wax rubbed on the threads) to secure the decking to the joists. I left a 2” spacing between the decking and the tree trunk to allow for movement and future growth. (Photo 8)

Fig. 3

The VP floor system incorporated four major support 2x4s (full dimensional lumber) horizontal arms (HA) each having a 45-degree 2x4 knee brace set below that kicked back into the trunk from about 2/3 the distance out. (Fig. 3) These arms were positioned at 0, 90, 180, and 270 degrees around the tree trunk. The HA length was calculated using trigonometry to find the diagonals of the 8' square viewing platform less the diameter of the tree trunk at their attach level and then the result was divided in half. I used the tree's circumference at the HA attach level to come up with the tree's diameter. Next I took a piece of flat cardboard and cut a hole a taste larger than the tree's diameter to form a pattern. I placed it around the tree at the HA level to confirm if indeed the trunk was uniformly round or if I would need to adjust the HA's lengths to compensate for fluctuations. This cardboard pattern also served as a guide to position the interior ends of the HAs at each 90 deg. cardinal position. (Fig. 4)

Fig. 4

Fig. 5

Photo 9
Photo 10

Photo 11
The knee brace (KB) lengths were calculated individually taking into account variations in the width or tilt of the tree trunk at their lower end attach point in relation to the HA attach point above. These variations were found by plumbing down to the KB attach level from the cardinal positions of the HAs on cardboard pattern and noting the actual isosceles triangle's leg length for each KB. (Fig. 5) With that measurement, the KB lengths and hanger positions could be calculated using trigonometry. Obviously, a KB having a longer length would have its hanger positioned lower to accommodate the increased length while a KB having a shorter length would have its hanger positioned higher.. The KBs were notched into the underside of the HAs and the two were connected with plate straps installed along the sides. (Photo 9)

These 4 units had to be killer strong as they were the foundation for the entire VP. Both the horizontal arm and knee brace sat in specially fabricated 1/4” thick hangers that attached to the tree using a single 5/8”x 4” galvanized lag bolt. Short ½” through-bolts kept the interior ends securely fixed in the hanger pockets. (Photo 10) Since there would be an outward pulling tension force at the interior end of the HAs as a result of weight on the cantilevered part of the joists, I ran a piece of 3/8” wire cable around the trunk through each of the 4 support joists about 8” away from their ends. This made it impossible for the support arms to pull away from the tree. (Photo 11)

Since the bottom ends of the knee braces would have a compression force against the tree trunk as a result of the VP's weight, separation would not be a problem so I only blocked this end to add rigidity. (Photo 12)

Photo 12

Next I installed some a ring of temporary 2x4s connecting the outer ends of the support arms to lock them into their correct 90 deg. positions while I installed 2x4 girders around the perimeter of the viewing platform. These girders were hung below the four support arms using carriage bolts and would carry the loose end of the intermediate finger joists. (Photo 13)

Photo 13

The floor decking for the VP was cut on the ground and installed in the same fashion as was done with the ETH but while the floor for the ETH was a simple straight run having all the decking boards cut to the same length, the floor for the VP was a constantly decreasing four sided square where each ring of boards was 8” shorter than the previous ring. It was more work but sure looked nice. 
(Photo 12)

Photo 14
Fig. 6
I decided to frame the living structure situated on the ETH floor platform using an unconventional method. Not only is it impossible to use nails in Guayacan without predrilling but my gut told me that with the strong winds and tree movement, the standard wall to roof framing connection methods would eventually loosen. Therefore, I chose to inseparably connect the vertical framing members of the wall (studs) directly to the horizontal members of the roof (shed roof rafters) to create a solitaire “n” shaped truss unit similar to the rib of a boat hull. This connection between the stud and rafter was made with a single ½”x 8” machine-bolt sent down from top edge of the rafter straight into the vertical shank of the stud directly below. I used the “perpendicular intersecting hole” technique (Roof Cutter's Secrets pg. 260)
to position a nut and fabricated square washer inside the stud to catch the bolt from above. I also applied some wood epoxy on the two fitted surfaces. (Photo 14) I assembled five of these “n” shaped wall/roof truss units to be spaced at 24” OC starting from the back of the 7'x12' platform going forward. One side of the “n” shaped units had a stud length of 6' above the floor surface while the opposing wall had a stud length of 7' above the floor surface. The height difference between the two walls created a 12” shed roof drop across the 7' wide floor. Once these units were stood in place, the lower end of each stud was attached to the outside face of the two long rim joists using two ½”x 6” carriage bolts. A 1”x 8” notch was made at the very bottom inside edge of each stud to facilitate placement while providing a solid bearing surface that supplemented the shear value of the two ½” bolts. (Fig. 6) After the skeleton of the ETH structure was in place and plumbed, I stick framed the front and back end walls, together with the window and door openings using the same “intersecting hole” machine-bolt installation technique.

Photo 15
Photo 16
Photo 17
On top of, and perpendicular to the shed roof rafters, I installed flat 1x6s at 24”OC to carry the metal sheet roofing (actually it was a fiberglass version of the same). These 1x6s ran long on the front and back of the building to create a 12” overhang where a 2x4 barge fascia board was installed from below to finish off the eave detail. (Photo 15)
The roofing was installed, the building was sided (Honduran pine ship-lap), the windows and doors were installed, and everything was trimmed out. On top of the roofing I screwed down pieces of ½” PVC pipe around the perimeter to keep the wind from grabbing the outside edges of the roofing sheets and ripping them up. (Photo 16) Where the tree passed through the roofing material I installed strips of 4” wide aluminum coated roof seal tape to close off the opening. This tape would need to be redone yearly if one wanted to keep rain from entering around the trunk. I had the idea to install an aircraft tire inner tube around the tree trunk at the roofing level to close the gap and make it water tight but never got a hold of one of these tubes so it goes untested. One would need to cut the tube open so it could fit around the trunk then glue it back together. Once inflated I believe it would provide a good water seal while accommodating the tree's movement

 I finished off the interior with the installation a few shelves and 4 trick “hide away” beds that folded into the wall framing when not in use. (Photo 17)

Photo 18
Photo 19
The stairway to the ETH was fabricated using 4” galvanized steel “carriolas” (thin gauge metal C-joists). I chose to use a 11” rise and 6” run for the stairway pitch (+/-60 deg.). This pitch, although steep for standard stairs in a normal house, seemed to have the correct feel for a real tree house. Because the tread was open and there was a good handrail it was no sweat even for an old guy like me to motor up/down. (Photos 18, 19)

Photo 20
Photo 21
Since kids would be undoubtedly be leaning over and hanging on the handrails some 15' up in the air, I wanted the handrails for both the ETH and VP to be bullet proof strong so I decided to use the same “intersecting hole” machine-bolt connection to attach the handrail to the balusters. (Photo 20) The lower end of the balusters themselves where attached to the 2x8 rim joists on the ETH using two ½” carriage bolts in shear (Photo 6) , while on the VP (which was built using smaller sized 2x4 joists), angled metal straps installed at the intermediate balusters provided the required rigidity. (Photo 13)  

To avoid hand rail separation at the VP's 90 deg. outside corners, small 1/8” steel plates spanning from bolt-to-bolt just under the wood hand rail were installed. (Photo 21) One would need a tractor to take these tree houses down.

Photo 22
Photo 23
Photo 24
The last project was the cable car. I strung a 100' long strand of 3/8” wire cable from the eucalyptus tree located on the far edge of the VP to the ETH's porch situated trunk and tensioned it into place using a come-along style hand winch. I placed drilled 2x4 spacer blocks around the trunks to keep the cable from strangling the tree. On the VP end of the cable, I circled the trunk twice and tied it back to itself. (Photo 22)

On the ETH end of the cable, I circled the trunk twice and tied it off at the inside end of the KJ's supporting 1.25” steel pin. (Photo 23)

I originally fabricated a 2 person cable car (passengers facing each other) but found it was too heavy for the situation so I chopped it in half to create a single seat version. (Photo 24) With an overhead pulley assembly one could easily whisk back and fort between the two platforms. (Photo 23) Lots of fun even for older kids like me.

Check out this video which gives a tour of the completed ETH and VP including using the cable car to travel back and forth.

NOTE: Unfortunately, not being a great computer person I lost the digital file containing the photos which documented the construction process. I returned to the job site in 2014 (5 yrs later) and took all the photos that are included in this article except Photos 6 and 12. Notice how the years of tropical weather has greyed out the beautiful natural Guayacan color.  Its brilliance could have been maintained easily with an occasional coat of varnish. Now it will take a little sanding to bring that color back out.

Copyright 2015 by Will Holladay

Sunday, March 9, 2014

A large overhang on a Dutch Hip roof requires a few changes to the normal construction method

In 2011, I was given the opportunity to frame up 4 small houses with Dutch Hip roofs on a remote island in the tropics.  I planned to use the experience to teach western style framing to the contractor's crew.

Panama canal zone Gamboa design
The houses were designed in the Gamboa style of the USA military Panama canal zone architecture.  This style was very effective in the tropics.  It incorporated huge overhangs to provide both abundant shade from the brutal sun and extra coverage around the house from torrential rains (22' average per year).  Temps in the shade during the day were always in the 90's accompanied by skin soaking +90% humidity.  Only at night did the temperatures become bearable in this carpenter's honest opinion.

The buildings were relatively narrow with 10' tall exterior walls.  The ceiling was “open frame” style 2x8 rafters/ridge at 5/12 pitch with 1x T&G decking above.  The Dutch Hip’s tiny Gable end walls were only to be perimeter framed then screened off to serve as roof vents.  During the day, the tropic sun would bake the metal roofing which in turn would transfer some of its heat to the air below the sheets and that hot air seeking to rise would find its way out these vents.   The rising air would draw cooler air in through the windows, facilitating a constant movement of air through the house, somewhat like how a chimney draws air up and out of the fireplace.  The interior partition walls were 8' tall and open above to the roof, similar to work station cubicles in a large office.  All the framing was to be done with imported treated Hondoranian pine, some strange wood that I had never heard of before.  I sure hope it works, since in this climate, mold and termites can knock an untreated wood structure down almost as fast as one can put it.

Reviewing the plans I noticed that the ratio of eave’s overhang distance to common rafter run was near 1:1.  While in latitudes farther to the North this would cause snow loading problems, here in the tropics with lightweight metal roofing as the norm and nothing other than rain (perhaps an occasional coconut) loading the roof surface, one would suffer no dire consequences from the design.  Of course with tails that long, one could anticipate a struggle when running the fascia.   With the birdsmouth located mid length along the rafters and the rafters themselves having varied sized crowns you can easily imagine the extra time that will be involved in jockeying the tails up/down to create a straight fascia line.

Original roof plan

I observed that the architect had drawn the Dutch hip ends to be framed in the standard method where short hip rafters frame to butt into a set of paired common rafters positioned at some distance in from the end of the building.  Normally, Dutch Hip overhangs are relatively short as compared to that part of the Dutch Hip framing set inside the building.  Most architects/engineers like to use a 1:2 or better cantilever ratio favoring the inside in these situations.  In other words, that part of the Dutch Hip framed inside the house is at least 2x the length of the eave’s overhang.  As a bare minimum, they want to see no less than a1:1 ratio unless a counterbalancing force is incorporated.  But here in this case, the cantilever ratio was reversed with much more rafter length hung outside the building than the Dutch Hip framing protruded inside the building.  There was 6' of overhang versus only 4' of rafter length inside the building.  This was a major structural concern since the hip rafter tail alone would serve as the primary support for a 6' x 6' roof section (36 sq. ft.).  Evidently it had slipped by the architect unnoticed.  (Click HERE for short video clip on standard Dutch Hip construction)

What I decided to do was get permission to shorten the overhang distance by 1' making it a total of 5' instead of the called out 6', and then I would run the Dutch Hip’s “hip rafters” full length up to the main ridge rather than butting them into a set of paired common rafters.  I would use continuation jack rafters to frame in the small Gable like extension that is an integral part of the Dutch Hip design.  By doing this it changed the "as drawn" cantilever ratio of 3:2 favoring the outside of the building to a 5:7 ratio favoring the inside of the building.  Personally, with the big eaves, I would have liked to have seen doubled 2x8s used as the hip rafters versus the specified single 2x8 but since I was only there to help with the framing, not redesign the buildings, I would stay out of the architect's realm unless I saw blatant errors. The material for the hips had been delivered per the original drawings so with my change they would now be short to reach the main ridge.  To reorder longer lengths would delay the project better than a month so I chose to "stretch" those boards by structurally joining them to another piece of 2x8 utilizing a dovetail joint.

Step 1 - overlay and mark

Step 2 - cut
Step 3 - assemble

The dovetail joint is detailed in "A Roof Cutter's Secrets" page 115.  Click HERE to view a short video clip from DVD2 of the "Roof Framing for the Professional - the Essentials" video series where I demonstrate making the dovetail joint to join two boards for a long ridge.

While I did not specifically detail how to do this special type of Dutch Hip framing in "A Roof Cutter's Secrets" (RCS), the book none-the-less includes all the background information needed to accomplish the task.  Cutting regular hip rafters are shown on pages 63-67, so nothing new here.  Continuation jacks are nothing more than regular valley jacks (RCS pages 97-98) installed from a ridge to a hip versus their normal usage from a ridge to a valley, so nothing new here either just a different application (continuation jacks are pictured on page 105 of RCS).  The Gable like extension at each end of the ridge could also be framed in layover style using CA valley jacks (RCS pages 97-98) if the full hip end was sheathed all the way to the ridge.  That wasn't an option on this project since the roof surface under the Gable like extension was to be left open for venting purposes.

Click HERE to view a short video clip from DVD1 of the "Roof Framing for the Professional - the Essentials" video series where I actually spend a minute in the classroom presenting this particular "hips to main ridge" Dutch Hip situation.

Edge of hip flushes with ridge

So for these 4 houses, I ran the main ridge well past where the full length hips would tie in so I could incorporate the Gable like extension.  With the ridge run long at each end of the building, there would be no standard "end-of-ridge" king common rafters to position the tops of the hips during stacking so I pulled up a temp “end-of-ridge” king common rafter (reg. common for the main span) to use as a marking guide.  I slapped it alongside the ridge and pulled the birdsmouth tight against the outside wall, then scribed the head-cut when the top corner edge flushed with the main ridge.  After transferring this plumb line up and over the top edge of the ridge to mark the opposite side, I used math to locate the hip intersection plumb lines at the far end of the ridge.  Recall that the distance along the ridge between those two sets of plumb lines would be the same dimension as if the ridge had been cut to an exact length for a full hip situation (RCS pages 63-64).  The math to calculate that length is: building length less building width, plus thickness of the ridge, equals the actual ridge length.  When stacked the top centers of each pair of hips would position at those lines.  RCS page 123 shows proper alignment of the top LP edge of a single cheek hip at the top edge of the ridge.

Hip rafter plumbed and braced at outside corner
When stacking the hips, plumb and brace the bottom of the hip at the outside wall corner.  This will make installing jack fill much easier.

Step hip jacks larger from corner to simplify frieze blocking

After we had the roof skeleton up (a few pairs of setup commons plus the hips), we went back and installed the hip jacks, the common rafter fill, and ran all the frieze blocks.  Since the frieze blocks were exposed they were placed at 90 degrees relative to the top surface of the rafter abutting the outside wall.  As most know from RCS, I start my jack layout from the building corner with exposed frieze blocks as this negates having to install tricky frieze block with a double compound miter at the hip rafter. 

Continuation jacks are used to help frame the Dutch Hip end

Now it was time to finish off the little Gable like extensions at each end of the ridge by installing the continuation jacks.  Because I had run the hip jacks full length on the ends of the buildings to strengthen the dovetailed hip rafter (rather than heading them off at the Gable extension), the 45 degree cheek-cut at the bottom of the continuation jacks needed to be clipped slightly to fit (see photo).  Remember these jacks must plane in with the far side of the hip, so hold them up accordingly.

2x4 cleats are used to straighten the hip and support flyer jacks

Since the overhang was so large we had to straighten the hip rafter tails with long cleats run from the installed hip jacks.  This cleat also facilitated installation of the two sets of flyer jacks located along the hip tail.


Long pieces of fascia along the bldg sides help w/ corner load
We utilized the 2x fascia to help carry some of the eave's corner load by hanging full length 20' pieces along the sides of the building extending out to the hip tail at the corners.  This "diving board effect" works even better if the fascia's crown is placed crown down.

Roof framing completed with 1x decking installed
With the 1x roof decking installed the building really came together.

Scaffolding to work the eaves was set up 6'4" from bldg walls to center
Inside view of the large Dutch Hip roof vent

Copyright 2014 by Will Holladay