A bit OT: cavity wall insulation and 'hollow block' construction

Jul 18, 2008 11 Replies
C

I believe our 1950's bungalow is constructed with those hollow or cavity blocks (don't know the correct name. Double-sized concrete blocks with two cavities in them; look like an electronic figure 8 when viewed from above. Fell out of favour because they were so effing heavy to lift, AIUI).



Is there any DIY way I can tell if this type of block was used, short of knocking a wall down? Would a reputable cavity wall insulation company be able to tell? Am I right in thinking that if those blocks were used, then it's not possible to have conventional cavity wall insulation?


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O

Drill a hole into the wall. Look inside the hole with a borescope.

Owain

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J

Can you see the wall construction better in the loft?

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M

If blowing fibre in is impractical, polystyrene balls from the loft should work.

NT

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C

But assuming a conventional bonding pattern, won't the separators in the blocks coincide with the spaces in the blocks on the course below it? In other words, the wall consists of a lot of sealed compartments. Or isn't that the situation?

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C

Not something in my toolkit. Where would I get one; a tool hire place?

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C

From recollection, not easily, but thanks for the suggestion. I'll have another look.

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M

Dear Chris H Have you considered that it may be hygoscopic? follow the other suggestions to mark with a pencil expect it to dry if it will in several months or a year (not weeks) unless you dehumidify

Chris G

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M

We've not seen the OP's walls, so who knows for sure. The blocks I've seen though are figure of 8 type, like the OPs, and 50% overlap on each course causes the cavities to line up fairly well, resulting in lots of long vertical tubes with uneven walls.

NT

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C

OK, yes ISWYM. Sounds promising. Thanks.

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C

Eh?? I don't understand the relevance of a word of that. I think you must be responding to another post.

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