hot spot on internal party wall?

wellused

I live in an early 1960's semi detached house, the other evening I got my coat out of my built in wardrobe in my bedroom and noticed that one sleeve was warm, I felt the wall and there was a hot spot which must have been radiating through from next door, the spot was about two foot away from where the chimney comes up from the living room fireplace but the old lady next door doesn't have a fire in the hearth but does have a back boiler. The hot spot was confined to a small area of wall about six inches square, I have never noticed it before or since. Surely the pipe or whatever is causing this hotspot must be really hot to travel through a party wall, I would imagine that the wall is of cavity construction like the rest of the house so the heat travels through eight inches of brick and a two inch cavity can this be right. I haven't spoken to the old lady about this as I don't want to worry her, any thoughts?

Doozergirl

Houses aren't usually built with cavities between houses. Cavities are to help prevent damp. It's probably a constant heat travelling through one skin of bricks if she's keeping the heating on.

My in-laws' house is as hot as Barbados.

wellused

The floor joists are built into this wall would it be single skin?

marleyboy

Possibly a hot water pipe running from the boiler to the central heating.

Doozergirl

wellused wrote: »

The floor joists are built into this wall would it be single skin?

There's no reason why it shouldn't be. Builders build semis and terraces as one building.

If you look in the loft, depending on age, you'll probably see what's between you.

wellused

Maybe it is then I must say that the noise levels aren't bad from next door even when her dog barks incessantly, I did think it strange that heat could travel through a cavity and be warm to touch though.

27col

Don't knock it. Any free heating has got to be a good thing.
There is no requirement for a cavity wall between semi's, as the dividing wall is not exposed to adverse weather conditions..The walls are normally 9" solid brick or block.
Although, I wouldn't be surprised if some low quality builders did install single brick dividing walls.

teneighty

Cavity separating walls have been quite common for several decades, it provides improved sound insulation.

Probably worth mentioning to the neighbour in case they have had something done which has damaged the flue. In the 60's and 70's they had these hollow flue blocks that were the same size as a standard block and could be built into each leaf of the separating wall. It is possible that something like that has been damaged or cracked and is leaking flue gases into the wall cavity. Not sure the flue gases would be hot enough to make a hot spot on the neighbours side though, just a random thought really.

For peace of mind though I think I would buy a £15 carbon monoxide alarm for the bedroom just in case. If the flue is leaking you might get a longer sleep than you bargained for.

wellused

These houses have traditional chimneys with big chimney breasts, I don't doubt that houses can be built with single skin walls between semi detached dwellings but the 4 inch wall would be 20 foot high with one end of both dwellings upper floor joists built into it and the roof perlins too, I will have to get into the loft just to confirm how thick the dividing wall is.

wellused

Just checked the loft and the wall between houses has brick courses of alternate header and stretchers so it must be a 9 inch wall that pipe must be getting pretty hot to transfer heat through that mass.

Kiran

It depends how "hot" you are talking. But as has been mentioned above, if the heating is on constantly then the brick will heat up like a storage heater would.