Piecemeal post and beam frame assembly

[evjim]

I'm building a post and beam house. Much of my carpentry experience comes from a job building pole barns, so this has some influence from that. I decided on the piecemeal approach to assemble the frame as it can go up as I finish notching each part. I also recently read this is a common timber framing assembly method in Europe but I cannot find much information. The posts are 8x8s and 12ft tall. The center posts will be 18ft tall and support a ridge beam. The girts are all housed so that the exterior wall will sit flat on posts and girts.





The foundation is sonotube piers with a 28inch base at the bottom. The base is 4.5ft below grade. The soil is heavy clay and has cracked neighbor's foundations. The piers should hold up better to soil movement but we have also installed a foundation drain next to the piers that runs out to daylight and backfilled with a well draining gravel. I foolishly decided to fabricate the knife plates after the concrete was poured. And so they have to be welded to the rebar. It has been tedious with my tiny 80amp stick welder. The slab floor may be an earthen type of floor. It won't be finished for several months. I have not put in the lowest girt because I want to cut the concrete piers square so they look better.




I'd like advice on hanging the beams. They are 8x10s and came at 12ft 2in long. The center to center measurement of the post is only about 11ft 8in. All of the posts so far have a housing with a 1.5in deep seat. The original plan was to use Gusset plates. Then the beans can fairly easily slide in when the posts are up. I am wondering if there are any alternatives though. I saw knee braces can be added after


The wall will be sort of a Sip made on site, but only one layer of osb, not both sides. I really like the wrap and strap drawings I have seen on this forum. Osb would mount to the girts and posts. Then 4inchs of Eps foam. And last probably a dryvit stucco finish. There would be a tyvek layer before the Eps. All windows would flash under the foam.

I was thinking about mounting drywall first to the outside of the frame underneath the osb sheathing. If I use 12ft sheets, then no taping or cutting will be necessary except in the gables. But the weather can be pretty harsh and so I may just go straight to osb so that the drywall doesn't get destroyed before the osb goes up. Any ideas on how to finish the inside of an osb wall?

[fishfighter]

To finish out the inside of OSB, first you need to make sure there is a vapor cloth or Plastic covering. Then you can just screw your sheet rock right to the OSB. Another way, you can screw 1"x2"'s, 16" on center. Screw your rock to this. Doing it this way gives you a area to run wiring in between.

[Don P]

It might be worth looking into DensArmor Plus gypsum board.

It sounds like you have enough beam length to break them on top of the posts. That can be a tenon on the post tops or steel T plates to bolt everything together.

[Brad_bb]

Maybe you should show some pics of your connection methods.  I'm not clear if you are using traditional Timber Frame mortise and tenon joinery or plates and bolts/screws as is typical in Post and Beam.

[evjim]

The joints are pocketed but do use metal fasteners. But I'd like to find a way to maybe do the beam to post joint a little bit more like a timber frame. But with posts already up, I am not sure how a normal mortise and tenon would work. The two posts would have to be spread out to fit the beam in. I was hoping there is some sort of beam to post joint that slides in from the side?

Here are the beam pockets so far. Plan is to slide the beam in from the side and use Gusset plates. But I could add a mortise to them. Maybe a mortise doesn't have to be centered on the post and it can be on an edge?


Another picture showing the girts

[evjim]

Fish fighter,  I like the idea of using 1x2 to offset drywall and have space for wiring. I was planning to run the romex or conduit exposed and have it look a bit industrial.

One advantage I think to putting up drywall on the outside of the frame facing in is that our posts are 12ft on center and so a 12ft sheet of drywall would need no cutting or taping. The girts are 4ft on center going up.

Don, I have looked into the dens element sheathing. It is a cool product but very pricey here. The local dealer gave me a price of about $30 a sheet. Where osb is $11 a sheet and 12ft drywall is $13 a sheet.

Would the dens board be a structural sheathing? Because I figure with osb I won't need knee braces anywhere that I have sheathing.

[evjim]

Some update pictures

Using a winch to lift the 18ft tall 8x8


Building at the end of today

[Don P]

From the Georgia Pacific specs;

DensArmor Plus Interior Panels are not intended for sheathing applications. For sheathing applications consult our

DensGlassR Sheathing or DensElement™ Barrier System brochure.

DensGlass is the yellow panels you see sheathing commercial buildings, it isn't a good finish "sheetrock" panel though.
I've used steel strapping to make X's for bracing in retrofit work before, hiding it behind the rock. That comes from Simpson in 300' rolls if I remember right. Similar to the X braced bays in a post frame building. OSB is going to perform better though IMO, it is better connected. One issue there is that the panel is unsupported in the field. The studs in normal frame construction keep the panel from buckling out of plane, that is where the field nailing schedule comes from. The steel in post frame creates that stiffness with the ribs. Diagonal board sheathing is another option.
Where I was going with the top plate beam idea is to set it on top of the posts not between them. Put the tenon on top of the posts, the mortise in the plate beam and set the beam on top of the post. Hidden on the exterior face of those, strap the post and beams together under the rock.

[evjim]

Cool. I like the steel strapping idea. And I was concerned that my girt spacing and flexibility might not be tight enough for osb to be as structural as I intended it to be.

So you are saying the dens glass interior surface is not the same as drywall? Could it be tapped and painted? What kind of cost per board have you seen? What is the advantage of it over osb?

Thanks

[Don P]

The densglass is made for sheathing for fire walls. I've only seen it in 4x8 sheets ~$20. untapered edges. Without backup I think any drywall is going to give you trouble at 4' unsupported spans. You could attach it to the girts and posts, x strap, then vertical boards at 2' centers or closer attached thru the rock to the girts and plate beam, then come back from the inside and screw the rock to the boards. If you temporarily brace the posts from the inside, get the roof on, and then do the walls a bay at a time complete with siding regular MR board should be good enough unless you get serious blowing rain. Looking at the site start on the upwind side. Winter is dry moisture.

[evjim]

Made a bit more progress on the frame. The ridge beam is up and 95% of the girts. Need to go buy a few more. The headers are ready to go up in the next day or two. And then we will put up the rafters. All of this rough sawn 2X material is pretty twisted. Not sure how we will hold the twist out of the rafters (2x8x14ft).





Here is a picture of how the beams turned out. In addition to the gusset plates with 3/8 lag screws, 10 inch timberlocks are used from the top. They are sitting on a 1.5inch deep shoulder. I think I will add knees later to the post beam joints not on exterior walls.



I opted to just order OSB at the moment for roof and walls. The weather resistant gypsum options weren't too available here. The plan is to sheath it in OSB. The weather is turning cold and snowy fast so I just need to get it enclosed. Strap it with flat metal X strapping avoiding where windows and doors will be.

From the inside on the walls I will cut 2x (not rough, actual 1.5x) stud material to fit between the girts (laid flat). And then hang 1/2 inch thick drywall inside. It should be almost the same thickness as the rough sawn 2X girts. So the girt will still be partially visible. Hoping toenailing those 2x4s into the girts and drywalling will stiffen the wall significantly.

On the outside I need to create a drainage plane before installing the EIFS. The options are:
1. Using a liquid weather barrier. Then apply the EPS foam with a troweled adhesive that has grooves in the trowel. Those grooves create verticle drainage channel. A spray foam adhesive can also be used applied in verticle lines. This is the most common modern way to do reliable EIFS. But all of those products cannot be used very effectively now that it is below freezing everyday.

2. Use Tyvek Stucco Wrap. It is some crinkled tyvek and the crinkles are vertically. You use it in combination with another layer of normal tyvek. I cannot believe this stuff actually work. The drainage plane is so thin and compressible. The advantage is the tyvek is applied with staples and then the foam with 4.5inch long fasteners with big plastic foam washers. It can be done in winter.

3. Can apply normal tyvek over the OSB and then vertical furring strips to create a drainage channel. The instal docs suggest a plastic furring strip at least 1/4in thick. I suppose wood would rot in there. So I dont think this would help stiffen the wall assembly much and still had to do the studwork inside the wall. Maybe I could put wood furring strips under the tyvek and wrap the tyvek bumping over it? A bit unconventional install of weather barrier.

4. Maybe screw the EIFS idea and apply the EPS foam right to the OSB and then side over it later once I can afford nice siding. It changes what layer the windows are flashed to. I was looking forward to the eifs stucco look with rough sawn trim pieces. Hoping it would look like a traditional timber and stucco building.

[evjim]

The rough sawn timbers have a great circle sawn pattern on them. But also a lot of loose splinters. What is the best way to remove the splinters but not sand it flat?

Thinking some sort of wire brush on the grinder but that might be too aggresive?


And would boiled linseed oil be an acceptable finish on the timbers? They are douglas fir and were kiln dried some. They already have some significant checking.

Thanks

[Don P]

Look up an Osborne brush, Schroeders log home supply used to carry them. It us like a wire brush cup wheel but has nylon bristles with sanding grit in them, it works good at cleaning and smoothing without removing the character, I've used them on hewn logs with good results. I had a machinist friend make a threaded stud that went into the brush and chucked up in my right angle drill which worked well, a grinder spins too fast and will burn.

You could rip treated lumber furring strips instead of the plastic ones if you choose that route.

[logman]

I used my 6" random orbit sander on these hemlock timbers mainly so I could see my layout lines.  I think they really looked nice, it didn't take any of the circle saw marks off but really cleaned them up.

 

 

 

    

[barbender]

Looking good, where in Montana are you?

[Cosmo52]

makita 9741 wheel sander works good to remove splinters and retain saw marks.  I used the standard 100 grit wheel

[evjim]

Don, thanks for the tip on the Osborne. I found a similar nylon sanding brush at the tool store. It is effective but slow going. Might wait until it is shelled in to hit the important spots. The pressure treated furring idea is good. Could rip some pressure treated plywood.


Logman, that frame looks great. How long did it take to sand all the members? That is a whole lot of joinery. Hope I can learn that skill eventually.

Barbender, thanks. Near three forks. We have a view of the Bridgers from the peak of the lot... But not from the house.

Cosmo,  that looks like a very effective tool but probably out of the budget for a single project.


We put up a rafter today after lots of measuring and marking out. As they will all be exposed on the inside we are thinking of using only timberloks. Toe nailing will be a lot of visible fasteners and dings. The timberloks seem to be a code approved top plate to rafter connection to replace hurricane ties. We are doing it backwards by going from the rafter down into a header but that should be okay? And then the rafter is face mounted to the structural ridge beam. I could not find a ton of info on putting rafters on top of a ridge. So decided to go with this method. Also using a timberlok to secure it? We will block on top of the header between the rafters later. There is no overhang because the continuous rigid foam will wrap around. And then sheeting on top of the foam will overhang.


Do we need to oil the outside faces of all the lumber before we shell in? Peak temps are barely 30 degrees these days.

I'd always welcome a constructive criticism to do things better. Thanks for all the input.

[Don P]

That little brush gave you an idea of the finish the Osborne will leave but if you value your time get one, they are 4" dia and it goes a good bit faster... I did the same thing, that little one is somewhere in the barn.

The timberlocks are ok at the plate, check with the inspector if you have one. Up at the ridge I have my doubts. If you can get up on top of the ridge on a beveled cant strip it would be better. You can check their ESR for connection shear capacity, I suspect you'll be into a Simpson connector if you face mount. It's no different than any other joist sitting over a beam or flush to a beam, if you go on top block in between at each end. Holler if you need more I can probably find some details and code cites.

Years ago we built a kit log home outside of the Bozone backed up to the Bridgers. The main memory was my wifes truck tranny fluid bathing my windshield somewhere around Butte when we were inbound. I told her she put on my rose colored glasses :D. I had rejected 3 houses of logs a year earlier in SD for being too green, that set was at ~10% when we got to them out there a year or so later. It would have been more fun if they had been milled dry but we made it work. I worked another 2 sets of them near Duluth. I'd have to look at dates but they ran ~14%, the differences had more to do with local environment than time. I guess that's a roundabout way of saying you are in an area of harsh drying conditions, it is cold which helps moderate it, oiling will also help moderate surface checking, judgment call.

Edit;
Check out fig 20 in this publication, not quite the same but similar enough;
https://awc.org/pdf/codes-standards/publications/wcd/AWC-WCD4-PlankBeam-ViewOnly-0304.pdf
I prefer to not notch the upper end of the rafter but rather sit on a beveled ridge or cant strip but this is ok if you keep the notch as small as possible.

[logman]

I just sanded each timber before I did lay out and resanded to get the pencil marks off when cut.  Didn't take long.  If you look there are 2 of those pavilions.  I think they are the coolest frames I've cut yet.

[evjim]

For the shear Calc at the ridge. The timberloks package says 260lb. The dead load is 2ft x 14ft x 10lb plus lived load 2ft x 12ft x 30psf equals 1000lbs, divide by two equals 500. So maybe two timberloks? Or a few nails with the timberlok? And a strap over top? We don't have an inspector unfortunately (and kind of nice)


In that pdf, do they only strap the two rafters together and not even down to the ridge beam? It would have been a good idea to bevel the ridge before putting it up but I think too late for that unfortunately. Unless we spend a day taking them down which wouldn't be impossible

That's a great story, sounds like you've built all over the place Don! I'll try and ask the sawmill what percent they were kiln died to

[Don P]

We've gotten 18" of snow today I ought to cut a couple of 1' squares out and weigh it.

That isn't really a good connection. Even a strap over the ridge, down the backside and under the rafter to a timberlock there would have better strength. I'd personally rather have something supporting the rafter from the bottom.

Nails and timberlocks, the timberlocks are going to hook up right now under load, the nails being smaller and more ductile steel are going to slip some amount before hooking up. Mixing fasteners and assuming they are helping one another can be tricky.

Beveling a 2x to sit on the top of the ridge at the roof angle, a cant strip, is another way to get that bearing under the rafters if you set them on top of the ridge. Doug fir has a bearing capacity in edge grain of around 500-600 psi.

The strap requirement is really to hold the planes of the roof together down to the connection to each wall then down to the foundation connection. The rafters could be offset from side to side enough for them to lap over the ridge and then connected to each other at the lap.  Think of the building inflating, that is what the strap or lap connection over the top is about. In hurricane Andrew you might remember seeing roof planes blowing around. The toenailed connections of rafter to ridge let go, the strap or lap holds them together. Doesn't hurt to catch the ridge on the way over. The other thing was entire trussed roofs coming off, that is the tie between roof and walls.

[evjim]

Been awhile since I updated this thread. Still not done with the project; but it is roofed, insulated, and heated for this winter.


I insulated with 4inches of rigid EPS foam screwed to the OSB. About 1 screw per sqft. This added some rigidity to the expansive walls. And once the mesh reinforced EIFS basecoat was applied the wall became very rigid. It seems to be acting as a site built SIP. Inbetween the foam and OSB is a wrinkled building wrap that supposedly allows for drainage.

This flashing is for a porch I will be building over the french doors. A simple shed roof supported by heavy timbers.

All of the yellow on the foam had to be rasped off. It seems like an environmental nightmare but this is standard practice for EIFS.




Another coat is needed. The finish coat will be consistently colored. It seems like little changes in the amount of water added to the base coat and how windy/sunny it was at the time would change what shade of gray it dried. Solo tuccoing this house from a ladder took over a month off and on of work. Winter came very early this year and has delayed a lot of outside work days.






Pretty happy with how the 2x6 car decking turned out as a ceiling and floor. I primed the bottom side before installing. Not looking forward to adding a second coat of white paint up against all that rough sawn board edge.

In the background you can see I started drywalling. On the inside of the OSB I cut off the ends of the foam screws and screwed the drywall directly to the OSB. It is very hard to get the drywall to be the perfect size/shape to fit in there. Its going to need some touch up mudding around all the edges or lots of trim. Not sure how people normally deal with drywall abutting rough sawn?

[evjim]

The basecoat is 99% done now except around windows. Here are a few more pictures of the process.






All of the gaps between EPS foam was filled with sprayfoam. And then a fiberglass mesh is embedded in the wet stucco material.









I haven't figured out for sure I am going to insulate the slab at the doors. The slab is heated so insulating is important. But I can only fit about 1inch of thickness under the door lip. And then I need to protect the foam somehow. And fasten it all up. I am thinking 1in of polyiso adhesived to the slab and then a piece of aluminum adhesived to the foam?

[Don P]

Good progress, you can work in the warm this winter 8).

2" foam, bevel the top, form with a piece of removable plastic ~1/2-3/4" thickx1" or so down to the foam. Pull that strip out after the pour, insert a rope of backer rod foam and cover that at the surface with polybutyl caulk tooled with a masons striker or similar, dipped in mineral spirits. Look down at the floor seams, at the wall joints and wall to floor joints in a Walmart or Lowes. You'll need to keep out of it till it cures, they use a catalyzed 2 part version that kicks off quicker.

[evjim]

Thanks Don! Also, the slab has already been poured. It is insulated around most of the perimeter because the slab came out flush to the sheathing. And then the same 4in wall foam drops down below grade. Its only under the doors where I need to add some extra perimeter insulation.





Two inches of foam under the slab with electric resistance wire embedded. (Electricity is only ~5cents per kwh here do to being on co-op power and near a hydrodamn). A pex system with boiler would have cost $1500+ where as the wire in the slab cost $300 plus a contactor with a gfci breaker connected to the thermostat.

Used the pex staples about every 4ft. More often at corners.





Put rebar on top of that at 2ft centers. Did not use chairs to hold the rebar up because after testing that they just compress into the foam. I was very vigilant about lifting up the rebar as we poured.




Blocked out for this shower p-trap




Conduit for floor temp sensor so that it can be replaced later.




Poured through this door. Would have been much easier to pour a slab up front but the plumbing and heating planning were not ready when I wanted to start framing. And the funding was much easier to just pay for piers up front. I now see on this forum that piers are often not recommended.




Here was the pier foundation 7 months earlier. The trench was backfilled with drainage gravel and a foundation drain is buried alongside all the piers that empties out to daylight.




I hired a concrete finisher (so far only hired out 16man hours, besides my friend and I). But he had a hard time finishing up to the edges. Not sure if this is normal because the slab was poured inside or I just didn't pay enough for quality work. The slab will end up needing to be ground down or a very thick epoxy finish over acid etch.







Here is the edge of the slab, form partially removed.




Slightly worried about the frost heave effecting the slab independently of the piers. I may burry a 4ft skirting of sloped poly around the perimeter of the building to keep the soil dry. My understanding is only wet soil heaves. Have also considered burying a skirting of foam to keep the soil under the slab from freezing.

Also, just want to make sure this is an acceptable forum to be posting this build on as its not timber frame?