Insulating Old Mass Masonry Walls (For Architects + Contractors) 

*A Guide To Moisture Management For Residential Remodels eBook:* asiri-designs.com/shop

Fantastic information for anyone contemplating fitting or having internal wall insulation fitted. I'm based in the UK, where mass masonry wall are the predominant form of residential buildings.

I used InSoFast panels on the inside of my mass masonry walls instead of a simple mat/spray foam. Baffling on the masonry side allows air movement so moisture can spread out and find its way back out. Locks together at seams & spray foamed the edges to act as air/vapor barrier. Plastic studs inside the panels allow you to screw the drywall directly to it on the inside. Trickiest parts were electrical & penetrations. Spray foamed the hell out of them.

Terrific video!

I’ll need to get a copy! Thanks a lot for this.

Old historical urm buildings are my favorites to work on. So they will be around another 200 years. I Hate fixing those old chimneys that were built flush into the walls. I use dolomite and portland cement and sometimes hydraulic cement on stone rubble foundations below grade, but not on man made masonry or free stone materials.

You have the most informative videos in these topics that I’ve been able to find. Thank you for making these! Do you have a method of interior insulation that you’d recommend for a cinderblock wall with vinyl siding on the exterior?

Currently renovatting a large building in Pennsylvania. I am reluctent to put a Parge Coat on as I might want to have exposed bricks in the future. I plan on repointing the bricks, would this be enough? Thanks for all your educational content!

So I am doing something similar to your spray foam solution for my building. 40 years ago the previous owner put 1" XPS foam board against the brick, then built the 2x4 walls and fiberglass with paper on it. Seems to have worked well with little moisture issues. So I am improving the design a bit. Originally the plaster was attached to lath on the exterior walls. The lath was attached to vertical pieces of wood that were nailed into thin wood strips that were mortared between the bricks. After 160 years those thin strips aren't in great shape, so I am replacing them and adding back the vertical pieces of wood. I am then attaching the 1" XPS to those vertical pieces of wood. Then building my 2x4 walls and adding fiberglass and a vapor barrier. By biggest issue are the floor joists as they sit on the bricks. The brick wall gets thinner as it goes up to the second floor. And that creates a shelf on which the joists are resting. Between the joists they added bricks. So the joists are surrounded by brick on 3 sides. I am trying to figure out how to insulate it to prevent heat loss, but also trying to loose heat there so the wood can dry out without creating cold spots for condensation to form. It's very frustrating. And unfortunately there is not enough space to put foam board insulation between the joists and brick. Ideally I would cut the joists out of the wall and support them on the ground floor walls, and keep the joists entirely withing the insulated envelope.... but the ground floor is the area that was renovated 40 years ago, the second floor wasn't used and left untouched (mostly). So I can't rest the weight of those joists onto the walls below. In addition they carry a lot of weight due to the structural design choices made 160 years ago. Edit: so after typing up this comment, and browsing your website I am learning a lot of information! I greatly appreciate it! You even have a post about insulating beams in brick walls! Thank you!

I'm neither a builder nor do I have any brick walls to insulate. This video popped up in my queue so I gave it a watch. Fantastic information, and well presented! I'm curious how this would work with townhouses. I'm assuming the effectiveness would be much less since water from the neighboring bricks will want to move into your bricks.

I'm restoring a 1899 old German villa estate. I have deplastered all original exterior and interior walls to let it breath. I am now onto figuring out how to insulate from the inside. Not much info out there on old buildingd and am grateful to stumble on your video. Great work. I will be using steel framing...is there much difference in the procedure?

Great video! I live in an old brick brownstone in NYC and wanted to know how to insulate it from the inside. What's a good way to insulate the roof? It has a slight slope

Hi. Great video. I’m the example using rigid foam, what is the purpose of the simple mat? Where does water that drains from the dimple mat go? Could the simple mat be replaced with just an air gap of some thickness and the rigid foam attached to the back side of wood framing?

Can Prosoco Cat5 be also used in the interior masonry wall? Or the paint is a better solution? Triple wythe brick in NYC, I'm looking to insulate the exterior walls. Waterproof paint in the brick or Prosoco Cat5 barrier, rockwool batts in a 2x4 wood frame, Siga Membrane with Siga tape, sheetrock on top of the Siga. Will that be enough?

Hi! Could this method be applied to an old porous subgrade foundation wall in an area that experiences freeze thaw cycles? The concepts with the spray foam makes sense with the drainage plane and an unfinished basement space. Obviously it would be beneficial to waterproof from the exterior first however we are concerned about the costs associated with that method.