Installing Slate on Concrete Porch
Hi, all…would appreciate your advice. Our 1953 ranch house has a concrete front porch that is protected by an overhang. The front of the house is redwood siding and the siding rests on top of the concrete porch. There is no flashing or other waterproofing between the siding and the porch. Yet, after 51 years, the siding is still in excellent shape. We avoid hosing the porch down to prevent water entry into the joint between the siding and the porch. The stained concrete is really showing its age and I’d like to install 12″ ashlar slate tiles over the porch. Here’s the question: should I butt the tiles up to the siding and create a vertical joint? Or should I cut back the siding to slide the tiles under the siding to create a horizontal joint line? If I need to cut the siding, how would I do this? Lastly, should I use any flashing or other waterproofing between the siding and the tiles?
Any help would be most appreciated?
Steve D
Replies
should I butt the tiles up to the siding and create a vertical joint?
No. If you do, you will almost guarantee it to rot in a few years.
Or should I cut back the siding to slide the tiles under the siding to create a horizontal joint line?
Much better.
If I need to cut the siding, how would I do this?
If you must cut it while it's on the house, you'll probably be limited to a zip tool. If you're careful, the cut will be straight enough.
Lastly, should I use any flashing or other waterproofing between the siding and the tiles?
Yes. And this is the reason that the best overall method includes removing the siding do make the cut. You need to put some L-shaped flashing behind/below the lowest course of siding. The flashing should not touch the slate -- if it does, water will wick up.
NOTE -- since this area is protected by an overhang, all of this might be a moot point. If it has survived for a half century without flashing, it might survive that long after the change. How much weather does the protected wall take?
Unless you're the lead dog, the view just never changes.
Thanks for your help. The area takes very little weather -- faces to the west and most winter storms come from the south.
How would I terminate the flashing without having it touch the concrete? Is that possible?
Steve
You could cut off the siding the same way tilers and wood floor installers cut off door jambs: rent or buy a Crain saw. or you could use a biscuit joiner, or even use a hand-powered jamb saw. If youn cut off a half-inch of siding, what are you going to expose?
Whenever you are asked if you can do a job, tell'em "Certainly, I can!" Then get busy and find out how to do it. T. Roosevelt
Ed...thanks for the tip about the Crain saw. I was unaware that such a specialty tool as a jamb saw existed. I've seen jambs cut back manually with Japanese pull saws, but not the power tool. I need to cut into three internal corners -- I guess I'll have to somehow finish the cuts manually (or via chisel?) after completing most of the cuts with the Crain saw.
The siding is v-rustic 9" exposure all-heart redwood nailed directly to the studs (we had some siding off nearby to install new windows). I don't think there's any paper between the siding and the studs.