I started a repair on a lean to-shed, and the low wall sill is completely rotted away. So, my plan is to replace the sill with a pressure treated 6x6, use PT 4x4's corner and center posts, with a PT 4x4 for the plate - the wall is only 4-1/2' high.
I have a few questions - first of all, would I use a 1" tenon with the 4x4? I read somewhere that the rule was tenon thickness should be 1/4 beam width.
Second, for the braces I was going to use 2x4's. Considering the 4-1/2' wall height, what would be a good distance to put the mortises from the post? I was thinking 18". Lastly, if I follow the rule of peg diameter equal to 1/2 tenon thickness, I would use a 1/2" peg, and that seems small to me. What if I use a 5/8" peg?
One other thing - anything special I should know about timber frame joinery in pressure treated wood?
Thanks!
Sounds small to me all around, but what kind of snow load and overall dimensions we talking? Can you make it a 1-1/2" tenon?
Wear a mask when cutting up PT like you are. If you use a saw to make tenons you will be inhaling alot of dust. Avoid the PT sniffles and sore throat!
Quote from: Lurcherman on March 21, 2009, 09:34:47 PM
would I use a 1" tenon with the 4x4?
Yes, that is the rule.
Quotewhat would be a good distance to put the mortises from the post?
18" would be fine.
Quote
if I follow the rule of peg diameter equal to 1/2 tenon thickness, I would use a 1/2" peg, and that seems small to me. What if I use a 5/8" peg?
follow the rules, use a strong 1/2" hardwood peg.....
Quote
One other thing - anything special I should know about timber frame joinery in pressure treated wood?
As mentioned when creating dust wear a dust mask, also dispose of the sawdust properly.
I'm using PT 6X6 for my sawmill shed, doing some shoulders to help stabilize against wind from the next Katrina. I find a lot of inconsistency in PT lumber- not the best to start with and the PT isn't uniform throughout, just as you'd suspect from the way the process is carried out. For example, I cut some 11/2" shoulders for braces and even at that depth, the exposed wood is natural wood color versus the green of the PT part- seems like I'm exposing wood that will not be as protected as the exterior. That being said, most of the exterior is as-received and should offer a lot better protection against all the kinds of bugs and fungus we have down here in the hot and humid Deep South.
I agree with the suggestion on protection- glasses and mask. For some reason, PT wood doesn't cut like regular wood, with lots of small pieces and chunks of wood flying out at random times. Been hit in the eye protection so many times while cutting PT wood that I don't even think about not using glasses anymore.
Good luck and don't worry too much about getting it just right- sometimes you just have to go ahead and practice at something to try it out and begin developing skills for later. Oh, and read Jim's topics at the top of this section- answers for all your questions are there.
Lj
The shed was not originally TF, just a slapped together farmer job. The original plate was a plain sawn 2 x 3. The sill was a 4 x 6 that was laid right on the ground. The rafters was 2x4's with a 10' span and 24" spacing. I think most of the structural integrity of this shed comes from the siding, which is tongue-and-grove red cedar bead board. It's built poorly, yet has still stood for about 50-60 years I guess.
Thanks guys!
I take it back. The shed is not exactly slapped together. Just unusual. It appears the foundation was constructed of 4 x 6 railroad ties, and the shed framed on top of them.
I got the sill beam in place today, and the corner and center posts cut. I hope I have time to get the rest of it done this week!
Here's my progress so far:
(https://forestryforum.com/gallery/albums/userpics/17207/LowWall.JPG)
The sill beam is a 6x6. I had to dig out what was left of the rotten railroad tie "foundation", then use a masonry blade to cut the concrete that was poured into the rotten parts of the old sill to get a straight line. Then I backfilled with gravel and about 1" of stone dust to level the sill. I anchored the sill by driving 3' lengths of 1/2" re bar through it. I also pre-cut the mortises for the long sills. That way if I have to replace the remaining side walls, I don't have to worry about that part.
The gable end rafters are 2x6's, as I raised the low wall of the shed by about 4", and using a 2x6 gave me something to re-nail the siding to. The gap will be covered by the trim. I'm going to use polycarbonate roof panels, and so rafters are on 23" centers (so they are evenly spaced) and the purlins on 24" centers. Everything is screwed together with Timberloks. It is surprisingly solid, even though I have a couple more purlins to put up.
It's taken a long time to get this far, between rain, work, business trips, and a statistics class. I'm hoping to get the roof finished this weekend.
If nothing else, it has definitely been a learning experience, and I now have an even greater appreciation for Barnwrights of old - true craftsmen that put my sloppy joinery to shame. I did get better as I went, and I did about 85% of the work with hand tools. If I'd just built it out of dimensional lumber using my nailgun, it would have been done in a weekend. But this was a lot more fun, and hopefully I'm creating something that will outlive me.
I just wish I could post a bigger photo, or link to the ones I have on Phot0bucket...
Looks nice...you should feel good about the project.
I also have pics in my --Photos MUST be in the Forestry Forum gallery!!!!!-- account. When I edited my FF profile info, I added my --Photos MUST be in the Forestry Forum gallery!!!!!-- account as my "website". When asked for my website description, I put in something like, "on-line photo sharing website"....and added the address. Check out my profile info and see. Maybe you could do the same. Good luck!
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