Insulating cavity walls, moisture, reliable providers

MichaelR

Hello,

I am in county Limerick.

Our house is built in the early sixties and it has cavity walls. (Except the converted garage). The walls are pretty cold, especially on the upper floor.

I was thinking of getting the cavity filled. A neighbour, however (and he's a great plumber too) thinks it is a bad idea, because in at least one house of the same build that he knows, it did not end well. The walls developed moist spots after the filling. As I understand this happens because rain water gets through, as the material (bonded beads?) does not let it slide down the cavity.

But the place definitely does need to be insulated. Internal drylining is not an option, too disruptive and affects space too much.

So, what options do I have? As fdar as I can think of:

- I can go for external wall insulation. Much more expensive, despite the grant. Also, might or might not need planning permission? But, seems to produce best results, right?

- Or else get the cavity filled after all, but get some kind of provider who would be reliable and would offer a meaningful guarantee, so that if moisture problems appear they would really remedy them - as opposed to claiming it's condensation. (Right now the house has zero condensation issues except in the shower room). Where can one find such a provider in Limerick or thereabouts?

- Or what else can I do? Get an engineer first maybe?

BryanF

Ventilation often needs to be increased after additional insulation is installed.

Bond beads/ insulating the cavity - doesn’t cause damp spots/condensation internally. What causes damp spots is likely to be a bridge Of material across the cavity, where for example the blockwork at reveals or lintels ‘break/bridge’ the cavity.

If you read around the forum, there is great info on all this stuff, some of the best threads are ~10 years back.

MichaelR

Thanks! But there are too many threads to go through them all. I would appreciate recommendations.

From what I did go through. it looks like, being in the Western part of the country, the prospect of cavity wall insulation does look questionable.

BryanF

You live by the sea?

MicktheMan

MichaelR wrote: »

So, what options do I have? As fdar as I can think of:

1. I can go for external wall insulation. Much more expensive, despite the grant. Also, might or might not need planning permission? But, seems to produce best results, right?

2. Or else get the cavity filled after all, but get some kind of provider who would be reliable and would offer a meaningful guarantee, so that if moisture problems appear they would really remedy them - as opposed to claiming it's condensation. (Right now the house has zero condensation issues except in the shower room). Where can one find such a provider in Limerick or thereabouts?

3. Or what else can I do? Get an engineer first maybe?

1. No. If the cavity isn't dealt with (i.e. filled), ewi will be of no benefit whatsoever. See 3

2. I wouldn't consider that until I'm certain that lack of cavity insulation is the reason for the cold house.

3. Have you considered how air tight (or not) your house is? Depending on house type and how it was built, upgrading your insulation may have no or little effect. Consider first having a heat loss survey on the house done first before spending money on "improvements".

MichaelR

I do have a spot thermometer so I can see the cold walls. However, a heat loss survey is probably a good idea.

I wonder if I can get the survey done by someone who can also validly evaluate best improvement methods while *not* affiliated with providers. Where do I look for the specialist for such a survey?

MicktheMan

MichaelR wrote: »

I wonder if I can get the survey done by someone who can also validly evaluate best improvement methods while *not* affiliated with providers. Where do I look for the specialist for such a survey?

Google "heat loss survey". You'll see from the results how independent they are.

MichaelR

Thanks, this worked, I wrote to a couple of providers.

padjocollins

please let us know how it worked out for u . there are endless people like you living in cold hard to keep warm houses

MichaelR

turns out -snip- does the kind of survey and recommendation that I was looking for. I'll report if/when I go for it.