Fixing a Hole (where the cold gets in)
February 1, 2014 9:48 PM   Subscribe

What's the best (most weatherized and solid) way to fill in a 22" square window well in a south facing concrete wall that happens to one side of my house?

The south side of my house, a concrete wall, has a big draft. I opened the sheetrock in the basement to take a look and found one likely source: a 22"x22" hole, filled with bricks and mortar, which is crumbling at the top. I saw a sliver of daylight instantly. It looks like an old window that was filled in.

Should I remortar the bricks? Pull them all out, fit forms and pour concrete? Something else?

If I pour, should I drill some holes into the existing concrete for better adhesion/joining? Add rebar? Thanks in advance.

Once I'm done, I plan to fill the gap between the sheetrock and the concrete wall with that solid styrofoam-covered-with-foil insulation, but am open to suggestion.
posted by msalt to Home & Garden (19 answers total)
 
To be clear, I'm not talking about a window well, meaning a hole in the dirt on the outside of a basement window. I mean the hole in the concrete wall that as formerly filled by a small window (I'm guessing.)
posted by msalt at 9:50 PM on February 1


I wouldn't go to the trouble of removing and replacing bricks because the window will be structurally sound regardless. How does it look generally on the outside? It might be time to redo the foundation parging. Youtube is generally a good source for this kind of DIY info.
posted by bonobothegreat at 10:04 PM on February 1


Parging? You mean the cosmetic skim coat?

The old window well is mostly just below the ground level, oddly. Only the top 1.5 bricks are above the current grade, and the air gap is between the top brick and the finished smooth top of the window hole; the mortar is very crumbled or simply missing there. No doubt it receives a great deal of water contact, as I'm in Oregon where it rains a lot and surface water would run right into this.

My house is hard up against the patio of a tavern next door. So from the outside this looks like a little corrosion in the plaster near the ground on one side of the patio wall, and it's not really my problem what it looks like.

I really just want to have a water- and wind-tight seal, which it clearly is not right now. And once I'm done, none of this will be accessible unless I rip open the wall again, which I'd really prefer not to do. I'm willing to do some extra effort not to have to deal with this again.
posted by msalt at 10:32 PM on February 1


Parging is more than cosmetic because it helps shed water. Old houses with brick foundations will usually have the bottom foot or two parted because water is landing all around the base of the house and splashing up onto the brick.

It's hard to picture exactly what you're talking about but it sounds like you have very limited access to the outside wall. This is a problem because unless you have some way of diverting water away from the brick, the corrosion is going to continue after you make the repair. For now, I'd just use spray foam (with a bit of steel wool pushed in first to discourage mice from eating through it.
posted by bonobothegreat at 11:02 PM on February 1 [1 favorite]


Is there dirt or the patio concrete just sitting there on the other side of the bricks, like if you took the bricks out it would be a simple open hole to below-grade?
posted by rhizome at 12:01 AM on February 2


Good question. Patio concrete and the edge of a raised bed planter box, at the top.

As for youtube, my question isn't about technique but strategy. I'm wondering about re-mortaring the lose bricks at the top, then painting the outside of it -- maybe both sides -- with some leftover Redgard I have from a bathroom tiling job, and then parging.

Redgard is a waterproofing material like liquid rubber. That's my main concern, water eating away at my patch from the outside, resulting in air and water leaks down the road.
posted by msalt at 6:56 AM on February 2


The main thing is to waterproof the entire outside. Don't do both sides, you'll trap moisture in the bricks. If you are inclined to chip it all out and start over, use concrete blocks, not bricks. And make sure that water running on the outside is not able to reach your sill plate. If the bricks are currently crumbling at the top, it's possible that's happening and you could have rotting in the sill.
posted by beagle at 9:03 AM on February 2 [1 favorite]


Thanks! By concrete blocks, do you mean cinder blocks or something else?
The sill plate is down at the bottom of the foundation, right? Surprisingly, there's not much sign of water coming in through the cracks between bricks (yet). I don't see evidence of moisture coming down the concrete. (Maybe the bricks are soaking it up like a sponge.)
posted by msalt at 10:24 AM on February 2


bonobothegreat -- I get along pretty well with the bar owner and I don't think he'll complain about any repairs I make unless they are very ugly and eye-catching. Good point on the parging, I hadn't thought about that.

Makes me want to get something like roof flashing in the crook there and parge over the top side of it..
posted by msalt at 10:28 AM on February 2


Here's a picture of the gap from the inside, with daylight visible and the outside view --. It's the little patch just left of the wood at the bottom.
posted by msalt at 10:40 AM on February 2


Cinder blocks would be fine, although you can also get solid concrete bricks.

The sill plate is the bottom wooden member of the framing, which sits on top of the foundation. Probably a 2x6 or 2x8. But by the looks of the pictures there is concrete above this opening, so not an issue.
posted by beagle at 10:45 AM on February 2


Thanks. Yeah, it's a crazy situation -- a 1900 wood frame house with what I thought was a masonry or cement wall a couple of inches ouside its south wall. But on close inspection, that cement appears to BE the south wall of the house. No idea how or why this would be the case. The wall extends past the end of the house on one side and seamlessly into the building next door, almost as if the house was just built right up into the side of the building next door. It doesn't really make sense, because there was clearly no building there in 1900, very early in Portland history.

Without tearing down the entire wall or ripping out the inside of the house top to bottom, I'm not sure how to even see what's there.
posted by msalt at 12:10 PM on February 2


Do you have a full basement or a crawl space?
posted by vapidave at 12:13 PM on February 2


Full basement. Available for rent in a month or so! It's a fully licensed duplex.
posted by msalt at 12:15 PM on February 2


Remortar and insulate. There is little difference between the insulating properties between bricks and concrete - and bricks, owing to being lighter and having more trapped air space are better than concrete at insulating. Replacing the bricks with concrete is not worth the trouble and is counterproductive.

After remortaring use canned spray foam on the periphery for insurance. Fill the void with your favorite insulation, hard foam has the best R value but is sometimes hard to fit. I like rock wool here.

"Once I'm done, I plan to fill the gap between the sheetrock and the concrete wall with that solid styrofoam-covered-with-foil insulation, but am open to suggestion."

Are you going to tear out and replace the sheetrock?
posted by vapidave at 12:49 PM on February 2


Related sort of...

When I puzzle crap like this out, I determine the time frame of interest for the repair. Are you wanting a 100 year, a 10 year, a 2 year repair? Makes a difference as to what approach you take, and obviously, the longer intervals are more expensive.

A 2-5 year repair here is insulating foam in a can, plus a little board of some foiled foam insulation from building site scrap, plus whatever cosmetics you want to address. 10 year is pointing up the bricks and mortar. 100 is removal, rebuild, surface match. Cost of the three would be $15, $150, $500. Time requirements.... 1 hour, 2-3 hours, 2-3 days. Anyone can do the foam, you can learn to do the pointing, and you'd want a mason for the latter.
posted by FauxScot at 3:17 PM on February 2 [2 favorites]


Figure out where the water is coming from. Check that the eaves troughs aren't sagging over that spot and that the down spout isn't partly plugged. There may be no standing water in light rain conditions but that can change after a few minutes of heavy downpour.

Most importantly, check that the ground slopes away from your wall. Water needs to drain away freely or it'll find it's way around any waterproof membrane you install.
posted by bonobothegreat at 6:58 PM on February 2


Excellent points, all. Unfortunately i have no control over the ground outside- there is no setback and my wall is also the wall of the patio next door. The patio is uncovered except for a seasonal tent whose corner is right next to this spot, so water will inevitably pool. That's why I'm thinking Redgard and even flashing under the parging.
posted by msalt at 10:38 AM on February 3


Sheetrock is already out; that's how I found this problem.

I have several vintage bricks maybe 100 years old; the crack in the middle pretty easily so I'm inclined to buy a few new ones for the four replacements unless there's a good reason keep the old ones.
posted by msalt at 10:47 AM on February 3


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