Framing question - Fixing an OOPS!

[Nick Sorenson]

Well I've been building a solar Kiln from these plans:
http://forestandwildlifeecology.wisc.edu/extension/Publications/98.pdf

But I have a bit of a problem. I'm not sure how but either the short wall is about 2" too short or the side walls (at 45's) are about 2" too tall.
http://img35.imageshack.us/img35/7804/dsc0003xb.jpg (http://img35.imageshack.us/i/dsc0003xb.jpg/)

The other problem here is attaching the bottom end of the roof in the center to the short wall. I really need to connect the roof to the short wall somehow so the middle isn't just floating.
http://img851.imageshack.us/img851/1434/dsc0004m.jpg (http://img851.imageshack.us/i/dsc0004m.jpg/)

So I've got two problems there. Any idea on what to do? I'm not much of a framer even though my dad was a carpenter. Osmosis didn't work too well ;)

[Chuck Wintle]

have you measured the walls and studs to see if they conform to the measurements in the drawing? to fill the gap I would put some extra 2 x 4's to fill the gap.

[keith ouellette]

Are you sure that gap isn't in the design? I am thinking moist air may exiting through that gap. If not then I would replace the the 2X4 that covers the tail end with a 2x6 or a ripped 2x8.

[Nick Sorenson]

Just figured the problem out. We're about an inch and a half to two inches short on the side wall end caps (the 45 degree walls). So I guess I'll be adding a 2x4.

I still don't see a good way to attach the mid section of the roof to the wall. Right now it's floating and there's a sag in the center kind of like the roof wants to slide down in the middle (since it's not supported).

[johnny means]

pick up a couple of your scraps and stand them on top of the top plate so that that they butt up sideways to the rafters. Cut the miter then nail in place.

[David Prince]

Option #3. Start over! OR...

Option #4. Hire a carpenter!

Even if you fill in the gap and nail it, it will lack structure. Each of the rafters should have a notch (birds mouth) so that the rafters tie into the top plate and keep the sidewalls secure and plumb.

http://homeconstructionshop.com/wp-content/uploads/2009/06/birdsmouth.png

[johnny means]

Even if you fill in the gap and nail it, it will lack structure.

It's a solar kiln:rolleyes: Pretty sure building code isn't really necessary here.

[Larry Edgerton]

It's a solar kiln:rolleyes: Pretty sure building code isn't really necessary here.

Code has nothing to do with it. Davids right, filling it in will add nothing. Davids birdmouth sketch its the way it should be done. As constructed you are counting on the integrity of the fasteners to hold it together, with Davids method you are counting on gravity. Which one lasts longer?

[Jim Andrew]

Johnny Means has it right. You could stand up a 2x4 scrap and mark to fit under your rafter, cut to fit the ends, and make the rest to match, nail those in under the rafters, then add another nailed onto the side of the rafter.

[James White]

Nick,

Part of the problem of filling in with scrap blocks standing vertical under the rafters is that when you nail them they will split apart. I would remover the trim board on the ends of the rafters. Plum up from the exterior side of the wall on to the rafter to get the mark for your plum cut of the birds mouth. Make that at least an 1 1/2" tall. Then make your seat cut 90deg (level) to that. Then you can rip 2 2"x6" to fit and nail them together (like a header). Or stack some more 2x4" plates to fill in. If you chose to stack the 2x4" plates be sure to make your plum cut the appropriate height to accommodate that.

By the way. Did the plans call for the wall studs to be 16" on center but have the rafters 24" on center. The rafters are supposed to line up with the studs below. Other wise you are bearing the weight of the roof on the wall plates that will eventually sag.

Come to think of it. you could remove your wall studs. Stack the needed plates at the bottom of the wall. Then fill your studs back in under each rafter. Just get 24" insulation to accommodate the wall spacing. 24" on center is just fine strengths wise for the wall. But 24" on center for 2x4 rafters if pushing it. The saving grace is the steep pitch of the roof.

I hope my rambling makes some sense.

James

[Darius Ferlas]

By the way. Did the plans call for the wall studs to be 16" on center but have the rafters 24" on center. The rafters are supposed to line up with the studs below. Other wise you are bearing the weight of the roof on the wall plates that will eventually sag.


There will be no sagging if the top plate is doubled (as it is in this case). Even residential building codes in many localities say it's just fine to have 16" OC studs under 24" OC rafters. The rafters here would sag well before the double plate. The codes are for residential and commercial structures.



Come to think of it. you could remove your wall studs. Stack the needed plates at the bottom of the wall. Then fill your studs back in under each rafter. Just get 24" insulation to accommodate the wall spacing. 24" on center is just fine strengths wise for the wall. But 24" on center for 2x4 rafters if pushing it. The saving grace is the steep pitch of the roof.

I hope my rambling makes some sense.

That actually makes sense. The 16" OC spacing for this particular application is definitely a structural overkill. What's more, the 24" OC spacing is considered thermally superior as the number of studs is lower in proportion to insulation. Other than the glitch with the double plate being too low I can't see any issue with the structure.

The technique illustrated by Nick is indeed the traditional way to rest the rafters on the plate, but so is another one, where rafter ties are used. More than enough for this application.

While the OP's implementation is surely somewhat botched, I wouldn't waste time on over engineering the fix. I would just plop sufficiently a couple of blocks of wood under each of the rafter, say 6 to 8 inches long. Nail them into the double plate, tie them to the rafters and, as long as there are no leaks, that thing will last a couple of decades to come.

Here is my little solar kiln before I insulated it:

- 10' by 4' foot print
- 380 bf capacity
- 2"by2" roof and wall structure
- 4" by 4" floor structure
- R9 insulation
- roof material is standard corrugated plastic, pretty skinny
- roof slope 49 Deg
- roof hinged and lifts up
- front wall hinged and opens down.
- best temp ratio 1:4 (outside to inside)
- max temp reading: 89 Deg C inside with 27Deg C outside.
- after the Winter with a rather generous amount of snow I see no structural issues with my " portable" kiln.

So far I dried 200 bf of cherry last year, green to 9% MC in 63 Days for 4/4, which is probably a little too fast. Lumber looks good but I did get some minor checking in the 8/4 boards.

[Ruhi Arslan]

I'm not sure how but either the short wall is about 2" too short or the side walls (at 45's) are about 2" too tall.

By looking at your attached plans, side wall should be 4' - 3 1/2" tall including the sill plates (Figure 4) and the rear wall should be 4' tall including the sill plates, two each at the bottom and top (Figure 3). When you place the roof overhanging the rear wall, bottom of the roof should be touching the outside edge of rear wall due to 3 1/2" difference (Figure 8). It looks like you cut the rear wall studs short. You can either take the rear wall off, cut 11 new studs to make it right or fill the gap with two more 2x4s. Plans don't call for birds mouth cuts or anything fancy. It should be an easy fix.

[Rich Engelhardt]

Just figured the problem out. We're about an inch and a half to two inches short on the side wall end caps (the 45 degree walls). So I guess I'll be adding a 2x4.

It took me a while to see that - but - yes - that's exactly what you can do. Put jack studs on the ends and it will move the 4' wall out.

I'm curious though..isn't there some exposed floor on the outside of the 4' wall?

[David Prince]

I didn't mean to sound harsh.

I too reviewed the plans. Yes, this isn't the Taj Mahal, but it still isn't an excuse for building something improper.

There are issues with the plans. The rafters on the headers and the rafters on the top sill plate lack integrity. The plans may work for this application as a solar kiln, but I hate to see people waste their time building something that could easily be built the right way with minimal effort.

I don't blame the OP at all. He was just following a flawed plan. Yes, he came up short, but my opinion is that it is a flawed plan.

[Nick Sorenson]

I didn't mean to sound harsh.

I too reviewed the plans. Yes, this isn't the Taj Mahal, but it still isn't an excuse for building something improper.

There are issues with the plans. The rafters on the headers and the rafters on the top sill plate lack integrity. The plans may work for this application as a solar kiln, but I hate to see people waste their time building something that could easily be built the right way with minimal effort.

I don't blame the OP at all. He was just following a flawed plan. Yes, he came up short, but my opinion is that it is a flawed plan.

Really it'd be easier or equal difficulty to do it right I think. But I figured the plans are good and just built them without much thought. Live and learn for next time.

But we got it to be pretty solid. Here's what my dad (union carpenter for 30 years) suggested when I mentioned the problem to him and I think it'll hold longer than I'll need this kiln.
http://www.rocketfireguitars.com/forums/other/Woodworking/DSC_0001.JPG

http://www.rocketfireguitars.com/forums/other/Woodworking/DSC_0002.JPGhttp://www.rocketfireguitars.com/forums/other/Woodworking/DSC_0003.JPG
http://www.rocketfireguitars.com/forums/other/Woodworking/DSC_0002.JPG
Then Sheathing will be screwed to the outside and inside to give a little more support to the added piece.

Another flaw I noticed is that the floor in the plans is 2x6 pressure treated. I think it'd be better to use 2x10's. It'd also be good if I had used a 6 posts total but oh well. It's almost done. I think it'll work for a good while.

By the way Darius, your Kiln looks great! Thanks for posting.