I thank all the folks who had helpful suggestions the last time I asked about this problem. I am finding that time and money seem to be getting in the way of my more ambitious solutions. Here are some photos of the affected area. The T-111 siding on my detached garage is rotting where it sits on the slab. The only affected areas are in the front where there is a sidewalk which catches water. There are gutters, but the roof doesn’t overhang the sidewalk enough to keep it dry. http://www.geocities.com/tommymc51/garage/garage.htm
The simplest solution is to just replace the sections of T-111 siding that are bad. It took them 15 years to rot the first time….. What if I do that, and cut the siding short, allowing it to stand 1/4″ above the slab. (the bottom plate of the framing is pressure treated) This would keep it above any standing water. Maybe run a bead of caulk under it? Is there an appropriate caulk that would adhere to wood and concrete? Or is this just a dumb idea………..
Replies
James Hardie makes cement siding similar to T-111.
Where is that available, and can it be stained to match the other 3 sides? I am staining the house and garage this summer anyway.
You can get hardi panel at Lowes or Meeks or other places that sell Hardi (I'm in Northern California).
Well painted Hardi will be better than t-111 but I would also look for ways to reduce the amount of water hitting that wall - at a minumum move the siding up the sill wall so you have 6 inches of clearance above the slab (if you have that much sill wall underneath the mud sill to work with).
You could put up a rock "veneer" up the wall to a height of 2-3 feet if you really want a big project.
1/4 inch won't be enough -- the joint will just fill with crap and hold water. You should hold the siding 2", or at the very least 1" off the concrete. And 4-6" is closer to "spec".
I'd say do more or less what I originally suggested: Fit in some pieces of cementboard (tile backer) at the bottom, just lightly tacked in place, fixing them in place with a filet of thinset mortar. If you can't get behind the siding with the pieces (no sheathing to remove), use a piece of Z flashing between the siding and cementboard, and back up the joint with a piece of wood on the inside.
Be sure to not overfasten the cement board, so it doesn't pull the thinset joint apart.
SS outside SS <- siding SS W SS|W <- wood joint backer ----W ^ flashing -> |CC W | CC W | CC <- cementboard approx 6" CC | /CCPPPPPPP | thinset -> ////PPPPPPP <- bottom plate/sill (drill weep holes) XXXXXXXXXXXXXXXXXXXXXXXXXX <- concreteEdited 8/9/2004 5:09 pm ET by DanH
Edited 8/9/2004 5:09 pm ET by DanH
So check me to see if I understand correctly. I'll cut the siding 6" up from the slab, remove the bottom, replacing it with cement backer board. Slip some flashing between the siding and cement board (the inside is unfinished, so is accessable) Then spread thinset mortar over the outside for cosmetics...so it 'looks' like a cement wall?
BTW, I didn't mention this before, but this is in an area that is likely to get bumped when we shovel snow, and although I am careful, the snowblower sometimes has a life of it's own. How will the cement board hold up to rough treatment?
No, the thinset isn't for cosmetics. You scrub the slab clean, maybe etch it a little, and use the thinset to bond the cementboard to the slab. Just a couple of 8ds hold the board in place otherwise, so it will stay with the slab if the framing moves a little. A filet of thinset between cementboard and slab keeps the water back from the wall an inch or so. Weep holes in the bottom plate (use a bell-hanger bit or an electrician's flex bit) keep water from building up between cementboard and plate.
Not pretty, but if you do it right it'll last 20-30 years with no maintenance.
The thin floor tile cement board (something like 3/8") is probably better in terms of matching the siding thickness, but if you want it to hold up to rougher treatment, use 1/2" (wall vs floor) cementboard. If a piece isn't wide enough, bond sections together with fiberglass drywall tape and thinset on both sides, and maybe back it up with a piece of plywood screwed across the joint as a backer. Or simply back the whole thing up with plywood, screwing through the cement board into it.
This setup would probably be about as tough as one could invent:
SS
SS
SS
SS|WWWWWW
----WWWWWW <--- 2x "fireblock" piece, toenailed to studs
|cc wwwwww
ccp
ccp
Gotcha, very good explanation. Thanks.