Insulating Existing Addition?

[Scott Hildenbrand]

I've got a perplexing issue.. The addition to this house was put on in a manner in which the brick was left in place.

Not surprising, I know..

This leaves an insulation issue though..

The rest of the room I am gutting and installing blown in cellulose into, including the ceiling and floor joists.

What to do with the brick wall though.... Currently the wall temp is 62 degrees, which is enough to get quite a bit of radiant off of and to cool the room.

My thought would be to remove the crown molding, drill holes in the mortar joints and to inject insulation in.. Question is, what kind.. It needs to allow any moisture to drip down, as typical, which makes foam a bad idea..

Any thoughts?

[Brian Effinger]

Just to clarify, are you saying that the addition was built up against the outside brick wall of the house, so the brick is inside the addition (and is now an interior wall)?

A photo may help as well. Once I have a better idea of the situation, I hope I can give you a good recommendation.

[Scott Hildenbrand]

That is indeed correct.

I'll see if I can put up a picture after work.

[Aaron Wingert]

It would be some work, but you could reasonably easily fur out the wall with 2x2's or 2x4's and create a wall space on the interior side that can be insulated. Radiant barrier faced foamboard would provide some R-value in the 2x2 space, or you could get an R13 with fiberglass batts in a 2x4 wall.

I only suggest that because you're gutting the rest of the room.

[Scott Hildenbrand]

That is indeed an option that I'd been thinking of.. Though I like the look of the exposed brick. Going with 2" foam would afford me R11.

[Rick Moyer]

What am I missing? You like the look of the exposed brick, it's about 62 degrees. You want to insulated it because..? Or are you insulating for sound?

[Scott Hildenbrand]

..... Because at 68 degrees set on the thermostat, the brick leaches mass amounts of cold into the room, which means the heat needs to be ran more/higher just to compensate?

[Scott Hildenbrand]

This is an old shot, but shows the brick just fine.. The far wall is what used to be a garage, but has been absorbed by the home.



The brick continues from the far wall, 24' to the right past the bird cage.

Starting to feel like the only viable option would be to fir it out and foam it.

[Aaron Wingert]

Fur it out, foam it, hang wonderboard and do a cultured stone veneer floor to ceiling. Nicer looking than brick, and no more brick heat sync!

(spending other peoples' money is sooooo easy!)

[Michael Wetzel]

If the brick is part of the interior wall now, I don't see how you will gain anything doing this. It would be like putting insulation between the interior walls dividing 2 bedrooms.

[Scott Hildenbrand]

Brick, by nature and construction, has a 1/2" gap behind it to allow water to drain instead of damaging the wall. This gap acts as an air tunnel where cold air outside enters and cools the wall. Once the brick is cooled by the outside air circulating through it, it radiates this cold back into the room.

[Brian Effinger]

Does the brick extend above the addition? If it does, it is sucking the cold outside air down into the living space. To compensate for that, you would need some sort of thermal break at the addition roof line. A thermal break is something that stops heat transfer from one object to an adjacent one. In this case, I think the thermal break would need to be a literal break in the brick and some insulation.

When the addition was built, the brick that was going to be inside should have been removed, and a steel lintel should have been installed just above the addition roof to support the brick above. The roof structure of the addition should have gone past the brick and connected to the existing wood structure behind the brick.

Your idea to fir the wall out, and put some foam in it should work, BUT you will want to install a vapor barrier to keep any moisture from hitting the brick. If it does, it will condense at some point up the brick wall and fall back down to the floor, rotting your sill plate and possibly eating away at the brick and mortar.

I hope that made sense. At least it did to me but I am in the construction field (an architect) and can visualize it pretty easily. Let me know if you have any questions about what I have said.

Brian

[Scott Hildenbrand]

Does the brick extend above the addition? If it does, it is sucking the cold outside air down into the living space. To compensate for that, you would need some sort of thermal break at the addition roof line. A thermal break is something that stops heat transfer from one object to an adjacent one. In this case, I think the thermal break would need to be a literal break in the brick and some insulation.

You've got it.. A classic addition against brick done wrong.. Brick goes from the bottom of the house to the top, all the way to the roof 1 story up.

When the addition was built, the brick that was going to be inside should have been removed, and a steel lintel should have been installed just above the addition roof to support the brick above. The roof structure of the addition should have gone past the brick and connected to the existing wood structure behind the brick.

Thank goodness someone understands how it SHOULD have been done..

Your idea to fir the wall out, and put some foam in it should work, BUT you will want to install a vapor barrier to keep any moisture from hitting the brick. If it does, it will condense at some point up the brick wall and fall back down to the floor, rotting your sill plate and possibly eating away at the brick and mortar.

So..... Fir strips.. Insulation between... Barrier over all that... Then drywall. Sounds like a plan.

I hope that made sense. At least it did to me but I am in the construction field (an architect) and can visualize it pretty easily. Let me know if you have any questions about what I have said.

Made total sense, but I'm a visual.. Can easily see things in my mind before they're done..

Ok.. Back to the thermal break idea at the top... Would it suffice to drill holes along the top and bottom of the wall and to spray foam into the cavity between the brick and the wall? My only worry with that is there are two windows at the second story on that wall. Both of which need replaced as they leak during very specific circumstances, which bleeds the water down inside the brick cavity just as it's built to do. Both would be replaced before I do anything, needless to say.

Any tips or resources for replacing windows in a brick home?