Adding some insulation to old brick house

mdelaurentisMarch 3, 2013


I have a 100 year old three story brick twin house in Philadelphia. I ripped down a 4' x 8' section of plaster from the ceiling in the front room on the first floor. It was pretty much fully separated from the lath there, and I had electricians working in that area anyway. I'm getting ready to replace that section with drywall, and I'm wondering if it would be a good idea to add some insulation. I've attached a couple pictures and I'll try to describe the construction.

Most of the joists in our house run side-to-side, but in the very front part of the house, the ceiling joists in the first floor run front to back. Inside, they're notched and resting on a double side-to-side joist, then they go outside where they form the ceiling of the front porch. I can't easily tell, but I suspect they're resting on a steel beam embedded in the brick wall. I suspect this because there's a wide window maybe 16 inches below the ceiling. So the front-to-back joists don't terminate in the brick wall, they extend maybe ten feet out over the front porch. There's also a bay window directly above.

When I opened up the hole in the ceiling, I felt a strong draft coming in. There is a gap of a few inches between the top of the bricks and the floor boards above. Beyond that gap there is just dead space in the ceiling above the front porch.

Would it be a good idea to add some insulation before I close the hole up? There was a thin layer of blown insulation above the lath when I pulled it down. I've seen that blown insulation in other spots of the house, and as far as I know that's the only type of insulation we have anywhere. I could spray foam into the gaps above the brick and below the floor boards to seal it up, or maybe just put in a fresh layer of loose insulation. I could lay bats in there, but it seems like plugging up the gaps in the bricks would be the best route. I'm just not sure if there would be issues with moister. I've read that moisture can be a problem when adding insulation to houses that don't have it.

I'm not sure if it's even worth it though, since it's a pretty big house and this is a relatively small area.

Any feedback would be appreciated.

Thank you for reporting this comment. Undo

Here's a photo of the area.

    Bookmark   March 3, 2013 at 12:29AM
Thank you for reporting this comment. Undo

I could spray foam into the gaps above the brick and below the floor boards to seal it up

Perfect. You're air sealing, not insulating. Never put fibrous insulation behind those solid brick walls or in the rim joist area of any house. It will get wet, promote mould growth and not insulate or air seal.

Here is a link that might be useful: Insulating Old Brick Buildings

This post was edited by worthy on Sun, Mar 3, 13 at 9:54

    Bookmark   March 3, 2013 at 9:46AM
Thank you for reporting this comment. Undo

if joists run from living space to porch roof, I'd bet
you have a situation like the one in the article
below. I've seen this in numerous existing
& new homes.

what did you find out?

    Bookmark   March 17, 2013 at 5:42PM
Sign Up to comment
More Discussions
interesting plaster job - what to do to fix it?
I'm doing some work in my dining room that includes...
Need color help with exterior paint on 1902 Victorian with bad siding
We have a 1902 victorian in a small town in Iowa. Unfortunately,...
Jennifer Weinman
Hi. I have never posted in this particular forum before,...
Stair striping and refinishing advice
I ve been stripping and refinishing my stairs in my...
Craftsman tile question
I recently visited a friend who lives in a beautiful...
Sponsored Products
New Cat Condos Mini Pagoda Cat House - 110017 - BEIGE
$92.99 | Hayneedle
Rue Royale Throw 72" x 54" - PAPARIKA/BEIGE (72X54)
$837.00 | Horchow
Black Circles Rug
$59.99 | zulily
A19 Lighting | Silk Scarf Wall Sconce
$319.99 | YLighting
Kichler Sayre Olde Bronze Pendant 1-Light
Artcraft Lighting Florence Gold Eight-Light 43'' Wide Chandelier
Landmark Lighting 66233-4 Barton Polished Nickel Vanity
Beyond Stores
Everly One-Light Olde Bronze Pendant
$182.60 | Bellacor
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™