Cavity Wall Insulation and prevailing wind

Techno

We own a bungalow which we rent out. The tenants are elderly and have asked about getting cavity wall insulation installed. My only worry is that the front of the house is quite exposed to the prevailing westerly wind and I have read that the wrong kind of insulation can cause the rain to bridge the gap in the cavity causing damp. Has anyone got any idea if this is true and if so is there a type that doen't cause this problem?
Many thanks

cyclonebri1

That was the original reason cavity wall insulation was initially introduced back in the very late 19th century, to address exposed coastal properties.
The batts used in new construction would not be affected, but after fill/injection is different and there are opposing views on this.

I suggest you google the issue to get the wider picture.;);)as I don't have a ready link.

anotherbaldrick

You would need to ensure the installer does the job properly and inspects the cavities and ensure that they, and more importantly the cavity wall cross ties are clean of mortar droppings before injecting the insulation. A cowboy outfit will not bother. That is when you get damp patches on the inner walls.

TimBuckTeeth

I certainly wouldn't get cavity wall insulation in my current house as it would get wet. A friend has recently had to get theirs removed after causing a damp internal wall.
If the construction and location of the house is suitable I would consider polystyrene bead insulation as it is less likely to absorb water and if loose bead type can be more easily removed. I don't think blown fibreglass is really suitable for cavity wall insulation.
I would get more loft insulation but be cautious about cavity wall insulation.

cyclonebri1

The stuff used to insulate walls by injection does not transmit moisture inspite of what others have stated.
BUT, it can form a bridge along which water/moisture can pass from outer to inner skin along the top or more likely bottom edges of the injected material

Google it.

Techno

I spoke to one of the guys that does the home energy checks and that was his comment particularly with the more solid foam type insulation - the water can run along it from outside to inside wall and other types can just become wet. Anotherbaldrick - they have had the offer from British Gas so not sure how good they are at this but I know almost all the energy companies are offering it for free at the moment.

ed110220

I always thought the problem was if you had wall ties with some mortar sticking to them (or other debris in the cavity) that damp could wick through this across the cavity. When the cavity is empty and ventilated, it is less of a problem because it can evaporate, but if you embed the mortar covered ties in insulation it can't.

barak

Here is one well-known view!

http://www.askjeff.co.uk/cavity.html

maninthestreet

cyclonebri1 wrote: »

That was the original reason cavity wall insulation was initially introduced back in the very late 19th century, to address exposed coastal properties.
The batts used in new construction would not be affected, but after fill/injection is different and there are opposing views on this.

I suggest you google the issue to get the wider picture.;);)as I don't have a ready link.

Late 19th century??

cyclonebri1

maninthestreet wrote: »

Late 19th century??

Yes, it gob smacked me too, but they were doing this before the year 1900.

You could of course apologise if you think you may have offended me for posting fact?:A:A:A:A:A