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[aaronjb]

Totally un-Omega related;

Anyone know roughly how much re-pointing costs (say per m2)?

The pointing on my place is bad in a few areas and to top it off nobody will fit cavity wall insulation as the pointing is raked out to >1.5cm (a design feature when it was built) over all the brickwork.. and anything I can do to stop the place getting freezing cold in winter has to be a good thing as it's by far the coldest house I've ever lived in!

[PhilRich]

1.5cm is a hell of a rakeout imo  , I would have thought 1cm at the most would be 'normal' for even 'architectural' reasons

[Entwood]

Don't know if this is of any use ....

http://www.whatprice.co.uk/prices/building/repointing.html

Personally I'd get 5 or 6 local firms to quote, and I always give them a printed sheet of what I want them to quote for, as they often try and change the spec so you can't easily compare quotes.

[Michael2.6]

I can not see why a business cant blow cavity insulation into the wall because it has not been repointed

unless you can see straight though the brickwork joints.

Pointing can be done by firstly cleaning out the brickwork joints with a small angle grinder and a 10mm thick diamond blade

then filling with morter mix with a hand board and pointing trowel.

[aaronjb]

I can not see why a business cant blow cavity insulation into the wall because it has not been repointed

Apparently (and so far two firms have told me this) - if the rakeout is too deep then water 'can' sit on the ledge made by the top edge of the brick, soak into the mortar, make the insulation wet and then (because the cavity insulation has filled the cavity and bridged what was a vapour barrier) make the interior walls damp & mouldy.. there's quite a few pages on t'interwebs about it being a problem in certain houses.

Mind, having said that, there are a couple of spots where I suspect I could poke a stick all the way into the cavity 

Thanks for the link Entwood, btw

And Phil - the architect who designed these houses added some very "interesting" 'design' features.. like random areas that are rendered block surrounded by the rest of the brick, and the top four courses (or so) of brick aren't actually brick but rather single skin block work rendered on the outside so the cavity stops about 9" short of the top of the house. Very odd..

[tigers_gonads]

I can not see why a business cant blow cavity insulation into the wall because it has not been repointed

Apparently (and so far two firms have told me this) - if the rakeout is too deep then water 'can' sit on the ledge made by the top edge of the brick, soak into the mortar, make the insulation wet and then (because the cavity insulation has filled the cavity and bridged what was a vapour barrier) make the interior walls damp & mouldy.. there's quite a few pages on t'interwebs about it being a problem in certain houses.

Mind, having said that, there are a couple of spots where I suspect I could poke a stick all the way into the cavity 

Thanks for the link Entwood, btw

And Phil - the architect who designed these houses added some very "interesting" 'design' features.. like random areas that are rendered block surrounded by the rest of the brick, and the top four courses (or so) of brick aren't actually brick but rather single skin block work rendered on the outside so the cavity stops about 9" short of the top of the house. Very odd..

How old is your house ?
Did it come with a NHBC waranty ?

[aaronjb]

How old is your house ?
Did it come with a NHBC waranty ?

42 years young (The house, not me .. it predates me by a few years) I'm not sure NHBC was around then..

Then again, measuring the rake tonight - rather than believing what British Gas told me it was - I measure it at more like 5-10mm (apart from a couple of bits on corners where it's worn back quite a bit) which sounds like it's within the guidelines for blown in cavity wall insulation; at least based on what another third party installation company ("InstaFill" in Reading) said. They also said "Oh yes, wasn't British Gas was it? They say that a lot.." 

[redelitev6]

No point( pardon the pun) in just repointing 5-10mm deep , it would just crack and fall out , needs to be a decent depth to have any strength

[JasonH]

You could get polystyrene bead insulation. It's rarer than blown fibre but much better. Because it's millions of small balls it doesn't transmit water across the cavity.

In our last house we had a wall that was really exposed and when it got really sodden water would literally flow down the inside of the cavity. With the beads there was no moisture problem and the effect on the warmness of the house was epic.

[aaronjb]

You could get polystyrene bead insulation. It's rarer than blown fibre but much better. Because it's millions of small balls it doesn't transmit water across the cavity.

In our last house we had a wall that was really exposed and when it got really sodden water would literally flow down the inside of the cavity. With the beads there was no moisture problem and the effect on the warmness of the house was epic.

That's what British Gas told me too - but the (only) place I found who still used poly beads said they worked to the same rules as rockwool (i.e. they wouldn't inject it if the rake was more than 15mm).. I'll have to try and find somewhere else that still uses poly beads and get a second opinion, clearly! Thanks