Building Firewall question

[Thomas Holm]

pacella wrote:
Can I safely insulate between the firewall of an occupied house and an empty building? I have a 2-story house that is 70+ years old and brick. It is a city semi-detached row home, meaning one wall is open to the elements. But the real problem is at the firewall where it is attached to an empty building. I've had problems with moisture (water) on the side where the two structures are attached. I know there is space (about 6 inches or so) between my brick firewall and that of the building. Can some type of insulation be put into that space to cut down on: a) the moisture traveling between the two and b) to keep my heat from escaping through that wall. I notice that the wall is always cool to the touch so I imagine because there is no balance of heat from the other side since the building is empty and abandoned.

This is a forum for mutual support from users of an architectural design computer application called Archicad.
Nevertheless, your question looks seriously meant, so I'll try to answer.
I have no idea of what climate prevails where your house is located, but if it is Chandannagar of West Bengal, India, I'd guess that the moisture issue is the worst.

- To control the moisture problem, you need to make sure that no rain can penetrate into the space btw. the firewalls, that is make sure the roof is intact. You also need to make sure the airspace is properly ventilated, both at the sides/bottom and through the roof. A knowledgable tinsmith should be able to help you make the roof both rainproof and ventilating the firewall airspace.

- To stop heat from escaping through the firewall, you'd actually have to do the opposite - reduce ventilation of the airspace in cold weather, and this would increase the moisture issue. You could use a fire-proof insulation material such as Rockwool, but you'd get two other problems from that - it would probably increase the moisture problem, and you'd have a very hard time trying to figure out how to get the insulation material evenly spread out and applied to your wall in the narrow airspace. Instead, I'd suggest you apply a heat insulation to the inside (your side) of the firewall. It has to be done properly to handle the moisture risk as well, but a local architect or structural engineer should be able to help!