PaulBartSpears

I don't have damp problems. My concern is that by insulating the walls they will get colder and then may suffer frost damage.

Thanks for your comment and the link.Very interesting. Apart from one isolated spot which I'm not too concerned about I don't currently have damp problems. They all occurred in the past before I owned the property and have been cured. There is render on the outside of some of the walls up to a height of about a metre which I think covers damaged brick. I'm concerned that by lowering the wall temperature by installing internal insulation frost damage to brick higher up might occur. Is this something architects know about? Are there specialists who know about this? One solution might be to render the walls if they get frost damage, but that might not be acceptable because we are in a conservation area.

You have it good. When I was a kid in Scotland it was so cold that there was ice on the inside of the windows and you had to break the ice in the toilet even when the heating was on. Yikes. My sister in law has just move into a super insulated new house in the Highlands, quite exposed, and rendered. Hope her render doesn't fall off. But I suspect there is something wrong with the local firm(s). I've seen houses in Northern Poland and Scandinavia with massive thicknesses of insulation and the render seems to stay on fine.

Very funny I'm aware of the planning, detailing and cost issues of external insulation, which is why I want to avoid it if I can. I can't show the (supposed) historical frost damage because it's been covered up by render. Being 170 years old there is no DPC. The areas that are covered by render on the outside coincide with areas on the inside that have historically had damp problems, though that seems to have been cured by some specialist internal plastering done in the last 20 years and maybe a chemical DPC before that. I'm no expert but I guess the historic damp problems were due to https://en.wikipedia.org/wiki/Damp_(structural)#Rising_damp My ideal outcome would be contact with some real expert who knows about this stuff, and who could, for example, measure the water content of the wall and test the strength of the brickwork, or come up with some mitigation scheme. I actually think the risk is quite small because I read somewhere that the wall has to be 90% saturated for it to be a problem. Most examples I've found were due to leaking pipes or are below DPC. Nevertheless I'd like to be sure because because the consequences of brick damage are fairly awful and would likely occur when I'm too senile to do anything about it.

Hello! We've recently moved into a Victorian house which is in need of some renovation. I'm 68 and my wife is 55 and we plan on staying here at least until I die. My calculations indicate that by insulating the solid brick walls to a U value of 0.3 I will roughly halve the heating energy consumption which currently runs at 22000 kWh per year. The house probably would not be suitable for a heat pump without the insulation, and I'm increasingly of the view that gas heating will not be available towards the end of my life, so I think insulating it now while I'm fit and sane is probably a good idea. So internal or external insulation? The house is big enough to take internal insulation and it would be cheaper as I can do the work myself and we wouldn't require scaffolding. My concerns are that the joist ends would rot or the brick would be damaged by freeze thaw action. The latter has already been a problem on some of the walls near ground level, and has been remedied by rendering up to about 1 metre above ground level. Presumably it has occurred here because the water content has been higher. How can I establish if the brick higher up is at risk through freeze thaw action after I insulate internally? Is this something architects know about? Are there specialists who know about this? Are there cheap treatments that keep the outside of the walls dry and hence reduce frost damage? It might not be acceptable to render the front of the house because we are in a conservation area. Thanks Paul