# How to insulate hidden basement window?



## ngk (Dec 27, 2012)

Hi everyone - looking for some advice. We just discovered a basement window and may want to insulate it, but I'm not sure how to go about it. 

Background: we live in DC and purchased the house 10 months ago (going through our first winter in it). House is a brick row house built in 1928; renovated the year before we bought it. Over the summer we had water seepage in the finished basement (tiled floor and drywall over brick on the walls) and had a trench and sump pump installed. Things were going great, no water, until this last month, with unusually heavy snowfall and rapid snowmelt. Water started leaking from the base of a wall in the rear of the basement. We had the waterproofing company back out; they tore off a section of the drywall on the rear wall and all the insulation underneath was soaked. 

Turns out there is an old window (next to a rear exit door) that probably was originally above grade and now is pretty much at grade. The rear of the house has new vinyl siding and windows in different places. Water was leaking through the window into the fiberglass insulation, which was wicking it away from the plastic drainage tile installed about 18 inches above the trench in the floor, and dumping the water in the walls and the ceramic floor tile. The waterproofing company's solution is to add more drainage tile all the way up the wall so that all the water coming in through the window gets diverted to the trench. I think that will work; even with just the insulation gone we can see water drip onto the drainage tile and the sump pump is starting to get more water in it. 

Sorry so long, but this is the main question: should we do something to insulate the hidden window? It looks like the renovator just put the siding up on top of it, so it is just windowpane-siding-outside. The basement has been cold this winter, but we thought that was just because it is a big basement with small vents, etc. it is also nice and cool in the summer. We have a guest bedroom and bathroom that get a lot of use, so we want it to get comfortable. However, we don't want to do anything that would interfere with the water draining into the new drainage tile. The waterproofing company will put in the tile, but the rest us up to us. 

Tl;dr version: we have an old basement window at grade with just siding over it. Drainage tile will be installed over it since there is frequently water coming in. Is it wise to put insulation between the tile and the new drywall? If so, what kind? (Also, are we completely wrong-headed in our approach to the window?) 

Thank you! Hopefully this is the kind of thing people have experience with. I am pissed at the renovator for just siding over the window, but at least it makes fixing the water problem more straightforward.


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## joecaption (Nov 30, 2011)

Basements need to be water proofed from the outside, not the inside.
That window hole should have been bricked or blocked up and water proofed before back filling.
Got some pictures of this whole area inside and out?


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## ngk (Dec 27, 2012)

Here are the photos I could take quickly. We didn't cut the drywall up all the way, so you can only see the window when peering up under the drywall. It seems to be about 18 inches tall and about 2 ft wide. It is under the siding between the spigot and the new window. The deck is above everything. 

I have only minor repair experience - how difficult would it be for a novice to do something to fill the window properly, once we remove the drywall and the window itself? I'm hesitant to hire someone since we are right now getting the roof replaced and a new driveway and fence around the backyard... But if it is the kind of thing that needs someone experienced, we could find a way. 

Thanks!


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## Windows on Wash (Aug 30, 2011)

New deck?

How as the ledger board flashed?


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## joecaption (Nov 30, 2011)

Got a real mess there.
Remove that trim (casing) from around the door, cut the tape line in the corner and at the ceiling so you can get all that drywall off.
No way should someone have even tried to finish out that basement without first addressing the moisture issues going on behind all those walls first from the outside.
Is that poorly pored concrete under that deck?
Who in the world built that deck and installed that siding?
Totally illegal the way it's built. Guess no permits where needed.
That freeze proof faucet needed a split block installed then the siding, not just a hole cut in the siding.
Let me guess, they also built the deck even with the threshold at the back to.


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## ngk (Dec 27, 2012)

The deck is new; previous owner (who did all the renovations) installed it. The deck was permitted and inspected by the city, so it's technically up to code. I have no idea what kind of flashing was used under the siding. The ledger board is installed above the siding, with just the bolts going into the house. Based on all the other things protruding from the siding with no flashing (the spigot, some vent pipes) I'm guessing there is no flashing. We haven't had water issues in other parts of the basement, and the deck is partially covered adjacent to the house, so hopefully rain isn't getting in. I'm sure moisture is coming in, but we might have to deal with that later. 

Thanks for the suggestion to pull up all the drywall. We'll do that and seal around the spigot (we were planning to do that soon to keep insects out also). You are correct - that is very poorly poured concrete under the deck. At inspection and right up until closing on the house, under the deck was gravel with an old drainage pipe (all the houses in this area seem to be originally built to drain their gutters into the city sewage pipes. At final inspection, all of a sudden under the deck had concrete. I could not figure out why (though they had been in the middle of other concrete pouring in the backyard, which was done very well. Maybe they had leftover and just wanted to use it? Or - in retrospect - maybe the basement was leaking obviously and they thought covering the area and trying to get all the water to run into the old drain would fix it.) 

We have had some French drains installed at the basement door (which is below grade), weeping holes put into the retaining wall adjacent to the door, a trench along the rear of the basement connected to a sump pump, and rain barrels to catch the pump water and gutter runoff. Neighbors mention that they have seepage issues also, but that sump pumps fixed their problems. Hopefully once we get this window fixed, the major water intrusion will stop. 

Would bricking the window (and installing drainage tile up the height of the wall) be effective, or do we need to tear off the siding and do something more extensive? 

Also, could the window be bricked up while the ground is still wet?


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## joecaption (Nov 30, 2011)

This is what was supposed to be used around that faucet.
http://www.lowes.com/pd_89145-835-1...currentURL=?Ntt=siding+split+block&facetInfo=
Siding needs to come off to install it.


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## ngk (Dec 27, 2012)

Thanks - that's what I was picturing. I'm so annoyed they didn't do it. 

Thank you for the advice!


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