Good morning,
This is my first post, been reading these forums for probably 20 years.
Let me explain my issue and see what everyone thinks I should do.
My home was built in 1883, brick construction, stone foundation. The entryway porch is inset so that it is covered on 3 sides by walls & the door. The previous owners placed some of the wood tile on the porch. There is a finished basement in which the porch is built over.
The porch is constructed of what I assume is a mortar bed, due to what I saw in the basement prior to finishing the ceiling. It appears to be like what you would find under a bathroom floor in a house of this vintage.
When I finished the basement below it, I did not notice water entering but now have staining on the drywall. During a recent rain, I noticed that I get water pooling on the interior wall-side, which would be an obvious cause of the leak. I’m sure the house & the mortar bed have settled over the course of 140 years!
With the background out of the way, I would like some suggestions for how best to make repairs to eliminate any future leaks.
I have my ideas, from reframing with a slight slope, 3/4″ plywood, moisture barrier (like a shower pan liner), Hardiebacker with HydroDefense (exterior rated, but not for Missouri), & finish with porcelain tile. Or, something that I’ve never done, a new mortar bed.
Please let me know your thoughts. I’ve added a couple of pictures of what I’m dealing with.
Thanks,
Steve
Replies
Treating it like a roof first is a good start, so yes to flashing, sloping, and waterproofing. You'll have to get flashing up under the siding, and I'd guess you're looking at some rot repair. When doing rooftop decks, one approach is using removeable panels so the roof below can be serviced.
Here's a link to an article I did with Manny Silva back when I was an editor at FHB. Search the site - Mike Maines has a good design piece as well. https://www.finehomebuilding.com/project-guides/decks/decking-over-a-roof
Thanks Andy. I actually remember reading that article!
I didn't even think about the siding. Something else to plan for.
Thanks,
Steve
That's a really nice looking front door by the way.
I had a similar issue on a balcony on our 1930's cape. It has walls on 3 sides as well. It was a small area, not slopped so well, and definitely had waterproofing issues. I went with the "shower pan" design and it's been great so far - one year.
What I did:
- Demoed out the existing. It was some vinyl thing with a membrane over it - it was a mess.
- Pulled up the plywood based and repitched it to 1" over the 5 foot depth. I didn't demo the joists, I sistered 2x6 to them to get the pitch.
- Put down overlapping layers of ice and water shield that ran 8" up the walls.
- Put down 1/2 wonderboard with stainless fasteners and thinset. Leaving a 1/4" gap around the edges. I ran 1/4 wonderboard up the walls about 3". Since I was re-shingling the walls and adding an air space behind them, this got overlapped by siding. Not sure that works for your case.
- I taped it and used redgard to waterproof it - two coats. Of course here is the controversial piece. Redgard is rated for indoor use (so using it outdoors will cause the end of civilization as we know it). That doesn't mean it will fail outdoors, that means there is added risk - which I was willing to accept. Also, I'm on the Oregon coast with very mild temperature fluctuations and the balcony floor is always shaded. Also we get around 90" of rain a year here - so I'm in fact building a shower base.
- I put 12x24 porcelain tile to finish it. Grouted the joints and silicone caulked the corners.
- I put PVC trim around the edges - it looked better than a thin row of tile would. I built a shower pan, but I didn't want it to look like one. This has the shingles coming down over it to lap for weather.
In general, if an assembly like this is going to leak, it's going to be at the edges / corners. I felt the ice and water shield, followed by wonderboard taped and redgarded, followed by the PVC trim & tile interface being siliconed - 3 layers of defense against water - was in order.
After a year, I very happy with the results. Stable, no cracking, waterproof, looks nice.