Cavity Wall Insulation Question

harryhound

Is this an air vent the cavity fillers have had to install, because you have some sort of fire/boiler using air from inside the house?

Bob63

My house had survived perfectly well for 90 years with an open fire and no vent in the lounge, but the installers insisted that one must be fitted so I let them do it. As soon as they left I covered it over inside with duck tape and that's how it has stayed for the past two years.

Ray_Lloyd

Hi Harryhound the vent is an existing one but the insulators joined the outer and inner with a pipe and yes we do have a gas back boiler and gas fire, as the air flow from out side is now very direct, e.g. can't disipate up the cavity it comes through at gale force so what i was thinking about was to stuff the vent pipe with open pore foam which would allow air through but not at wind strength.

regards Ray

Dealwithit

smellymel222 wrote: »

Hi
I am wanting to get cavity wall insulation installed in our home to save on our heating bills. However, my husband says that it blocks up all the air bricks in the house and someone has told him that this causes damp! Is this true?
Thanks
Melissa

Depends on what material the filling is. We have polysteyrene (sorry for spelling) in ours and get lots of condensation.

harryhound

Ray_Lloyd wrote: »

Hi Harryhound the vent is an existing one but the insulators joined the outer and inner with a pipe and yes we do have a gas back boiler and gas fire, as the air flow from out side is now very direct, e.g. can't disipate up the cavity it comes through at gale force so what i was thinking about was to stuff the vent pipe with open pore foam which would allow air through but not at wind strength.

regards Ray

Think I would invest in a carbon monoxide alarm at the same time.
I worked for a central heating supplier in the 1960's - even then there was quite a fuss when a family died.
The regulations are made on the theory that we all have an IQ of less than 80. "We noticed there were strange fumes (because we had not swept the chimney in 5 years) so we installed an extractor fan (and sucked all the exhaust gasses down the chimney)".
Gas is such a pure fuel, that the carbon monoxide is not mixed up with impurities, usually sulphur burning to sulphur dioxide, so you cannot smell the fumes escaping from a gas fire.

I always leave the internal doors open in the living area of our bungalow, to spread the heat and dilute any nasties.

harryhound

Dealwithit wrote: »

Depends on what material the filling is. We have polysteyrene (sorry for spelling) in ours and get lots of condensation.

Where is the condensation?

jeff_savepenny

Hi Guys, I have condensation patches on our exposed wall. It has been filled with urea formaldehyde foam nearly 40 years ago, it has some voids I'm pretty sure. The question is, can they be identified and topped up????

magicthise

Just the thread I have been looking for.

We recently bought a 1930's house with a brick cavity wall. Now when we bought the house, some idiot had decided to lower his heating bills by blocking up the air bricks with cement, which obviously after a few years, caused a little damp (not massively excessive, but its there). Anywhoo, we have a builder coming out next week to replace the air bricks and to clean up the cavity around them so it should be all nice and clear and let a good airflow move around the cavity.

Given all that, do you guys think cavity wall insulation is a good idea in a few months after the cavity has dried out properly or do you think that there could be issues?

javonliugd

Hi there, I equitably like reading your posts, sometimes non-standard due to you!

societys_child

There are many cases where the insulation has caused problems.

I had it done 5 years ago by a reputable company.The house is much warmer but some areas of brickwork now suffer from really bad efflorescence (salts coming to the surface) It's a mess to be honest and would be a problem if / when I want to sell. There are no damp problems on the interior.

The DPC is is fine and has nothing to do with the problem. Many buildings rely on ventilation in the cavity. I noticed there are now a number of companys specialising in cavity wall insulation removal. British housing stock is terrible (look at the problems people have, even with new builds) CWI is just another example of a poorly though out "quick-fix". IMO

I investigated by removing the odd brick here and there just above DPC level in the worst affected areas and the insulation is perfectly dry. As I said earlier - many buildings need ventilation through the cavity . . do a search. =cavity+wall+insulation (scroll down the page)

I'm not sure about the qualifications of the companys "surveyors" , just seemed like a sales person to me but when we were asked if we'd like 10" in the loft, my missus jumped at the chance, and they sent 2 fellas to do the job . . .:rotfl: