Wall Insulation query

Dormer Bungalow

Dormer conversion has no insulation behind the sloped ceilings.
Dormer is boiling hot in summer

Ground floor floor of bungalow has empty cavity and a sub floor for ventilation.

In winter ground floor is very cold
In summer ground floor is cool/warm (not hot)

I will be tackling the dormer insulation hopefully in the next few months.

I am contemplating having the cavity walls filled with beads.
My concern is if it will make the ground floor of the house too hot during summer (live on a busy road so ideally dont like opening the front windows).

Require the balance to be just correct. Correcting the dormer insulation may just go in hand with filling the cavity on the ground floor.

Suggest you post in the Buildings section, this is likely to be lost among the nonsense on here.

Admins - could you move to correct section please?

The short version is: more insulation keeps you warm in winter and cool in summer.

By insulating the walls and ceilings you're slowing heat movement from one side to the other. In the summer more insulation could make the ground floor too hot, if your ground floor is hotter than outside. If so, turn off the central heating.

IT Minion said:

The short version is: more insulation keeps you warm in winter and cool in summer.

By insulating the walls and ceilings you're slowing heat movement from one side to the other. In the summer more insulation could make the ground floor too hot, if your ground floor is hotter than outside. If so, turn off the central heating.

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Most of the houses we've lived in over the last 45 years have been Victorian or 30's, 9" solid wall. Our current house is 70's, cavity wall which has had cavity wall insulation installed.
Coldest house we've ever lived in. It could be because we're in an elevated position and the chill factor from the wind has an effect. We also have two small areas of damp, not rising damp, penetrating damp.
There was an article in recent years saying that anyone living in an area with over the average annual rainfall, ie, the entire West Coast, should avoid it because driving rain will penetrate a lot easier with cavity wall insulation.

If the wall is in good repair, it's not so much that the rain will penetrate, but it will not evaporate off the outer skin so easily. If the are mortar snots on the ties, or builders rubble at the bottom of the cavity (very common) it can allow damp to track across. Yo can have a look with a borescope, which some surveyors have.

it is possible to clean out a cavity, but rather laborious. loose sandy rubble can be taken out with a suitable vac. I did the wall of a bay once.

There are maps showing the areas of driving rain, they tend to be West country, West Coast, and high ground. I've seen the maps but haven't got a link.

One easy way is to contact your council or energy suppliers, who sometimes have subsidised schemes.

Because they can be forced to remove insulation at their own expense, they are very wary of houses at risk and will refuse to quote if they think it may go wrong.

An alternative that was used on my house in a coastal location is that the west facing wall is slate-hung to match the roof, and throws off storms like a waterfall (you need a gutter or porch above the back door); except that the first two metres above DPC is clad in shiplap, which is less prone to damage from people bumping into it.

mine was I think just intended to resist storms, it has battens and felt on the wall, but if I ever have it renewed, I would want to add insulating slabs for heat retention. Due to the storms, all the slates on roof and wall are centre-nailed and toe-nailed, and hardly ever fly off.

here you are.

Looks over-cautious to me, they've included more than half the country.




http://nhbccampaigns.co.uk/landingpages/techzone/previous_versions/2010/Part6/section1/appendix.htm

Steveb21 said:

My concern is if it will make the ground floor of the house too hot during summer

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No.

poly bead insulation is fine. it wont track water from the outer to inner brickwork, allows the cavity to still breathe and insulates.