Pumped wall insulation

cargen

Hi,

I am thinking to go for pumped wall insulation to retrofit a semi-detached house (build in the '50).

What is your view?

What do you think I should ask/check when I ask for quotations.

Any particular company to recommend in Dublin?

Thanks

Calahonda52

Are u certain its cavity wall and not cavity block?

I personally don't like this as a retro idea because you have no idea what the finished produce, U value wise, will deliver.
If its over pumped you may have some cracks in the wall, you have no QA on the actual product used, could be crap.
My issue with it you just can't see the finished product.

Have you dismissed EWI?

cargen

Calahonda52 wrote: »

Are u certain its cavity wall and not cavity block?

I personally don't like this as a retro idea because you have no idea what the finished produce, U value wise, will deliver.
If its over pumped you may have some cracks in the wall, you have no QA on the actual product used, could be crap.
My issue with it you just can't see the finished product.

Have you dismissed EWI?

Thanks for your feedback.
I would love to go with EWI, but I think it is much more expensive.
I am looking for feedbacks from people with retrofit pumped walls and see it worked for them,

JonathonS

As pointed out you need to check if its cavity wall or cavity block. In 1950s Dublin many of the builds were cavity block, which cannot be pumped.

MicktheMan

cargen wrote: »

I am looking for feedbacks from people with retrofit pumped walls and see it worked for them,

In the majority of cases, pumping the cavity (if there is one at all) with insulation makes little if any noticeable difference to the house. Reason being; conduction heat loss through the walls was not the prime heat loss mechanism to begin with.

BryanF

pumping the cavity is a good job, my folks did it in there house built in late 70's. Only spots of dampness on one wall where the oul fella dropped a big snot of mortar down during construction (100mm cavity with 50mm polystyrene)

But how do you know the quality of workmanship on your house?

the ewi is a much better option

Dudda

You should pump your wall cavity (if you have one) if you're getting external wall insulation. EWI is a big investment and without the cavity pumped you can create convection currents in the unfilled cavity particularly in two storey houses. Like what a radiator does in a room where the heat rises and falls in a room the same can happen in the cavity with EWI. This allows heat rise and escape through the cavity, roof and attic. Even if the cavity is poorly pumped it's usually enough to stop the convection currents and also it's a lot cheaper to pump that externally insulate.

If you pump with some foams you do have a small chance of cracks as the EWI expands but you can use the beads if you're worried about that.

My advice pump the walls now. You will feel a difference and save up a bit to get EWI in the future.