Cavity Wall Insulation

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I did do a quick search on this but still need to ask a couple of questions, my house is a 3 bed semi detached built in the 1950's. The external walls are poured concrete and in the winter its generally a cold house, we currently have the heating on 24 7 set to about 21 degrees.

The room stat is in the hall and I've turned the thermostatic valve on the radiator down to number 2 so the heating is on longer, as we have a new baby we have a wall thermometer in the room which wont shift above 16 degrees, the radiator in that room is to hot to touch, we tried leaving all the bedroom doors open and the temperature in that room got to about 18 degrees. This particular room has 2 external walls and are cold to touch so I suspect that is a large part of heat loss?

We have loft insulation Im not certain of the thickness and the windows are double glazed although could do with being replaced / repaired as they howl in high winds.

I assume I have a cavity even though its poured concrete walls?
 
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Cast concrete walls sounds a bit unusual I would have thought you have cavities though, go up into your loft and try and look down it from the eaves.
 
The most common poured instu concrete house was a Wimpey No Fines.
External walls were 8-12 inch solid. Many LA's retro insulated them externally because of condensation problems. Originally the No fines concrete was supposed to give more insulation than normal concrete.
I could e mail you the BRE report if you like.
 
that would be good, it is ex council my email is

Thanks
 
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Keep getting failure notices up Paul. Will try again later.
Try e mailing me
 
dam forum rules, I've added you as a friend so I can send you a pm as I didnt get your email address
 
You could drill a test hole somewhere out of sight or take a vent of an internal wall maybe.
If your still in doubt get a free survey off a cavity wall insulation company.
 
I did a bit of digging around and found that some authorities had refurbished some of these houses..this is what i found.

Wimpey No-fines
The properties were built in the 1950 - 1970’s and the construction is such that the
external walls are commonly 8 inches thick with a band of reinforcement - in bar
form - contained within cast in-situ dense concrete beams at eaves level. The
walls incorporate mesh reinforcement at first floor level and support above door
and window openings is provided by pre-cast concrete lintels. The external walls
are dry lined internally and rendered externally, although some surfaces of walls
may be tile faced or weather boarded.

In
addition, dwellings built after 1964 have timber load bearing partitions providing
substantial lateral bracing to the overall construction. In the unlikely event of
partial failure of an external wall, damage to the rest of the structure would be
limited.

The present refurbishment programme involved applying 95 mm of mineral fibre board (0.033 W/m2K) and render externally to the existing 250 mm ‘no-fines’ walls. Additionally, plaster was applied internally. This gave a resulting wall U-value of 0.30 W/m2K. This
U-value is 14% lower than the Approved Document L1(2002)
new-build value of 0.35 W/m2K, although it does not quite reach the indicative elemental standard for new-build houses in the proposed revision in 2005 of 0.27 W/m2K. In terms of sustainability, the system does receive an ‘A’ rating in the ‘Green Guide to Housing Specification’ for refurbishment of insulation.

Minimal internal disruption owing to the wall insulation being applied externally
• No loss to internal space for the occupiers (except for the loss of loft space for storage)
• Replication of the same works to a large number of similar houses
• High thermal inertia leads to avoidance of large temperature swings leading to high degree of thermal comfort in both summer and winter
• The refurbishment programme tended to lead to an improved appearance of the houses
Disadvantages
• Thermal bridge at wall-floor junction which is difficult
to eliminate
• Small cold areas remain on some of the walls owing to remnants of the existing warm air system which could not be eliminated.
 
jm thanks for that, will hopefully read Stuarts report over the xmas holidays and make a decision from there, it doesnt look that expensive which is a good thing
 
Paul,
Got your e mail, but it still keeps failing. Even a reply without the doc fails.[/img]
 
I was told a couple of years ago that I could not have wall cavity because I have a steel framed house and the steel needs to be able to breath, is there any other alternatives???
 

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