Cavity Wall Insulation

[dipee65]

When did it become a requirement under the Building Regulations that cavity wall insulation had to be fitted in new domestic buildings?

[weeal]

I cant find anything stating that its Law but its deffinitely advised under the new energy efficiency rules etc

Building Regs are different area to area tho

[dipee65]

Thanks for that weeal. I know it's a current requirement, in fact I think the U value performance has been increased fairly recently. I have a friend whose house was built in 1984, and is curious to know if the regs would have required wall insulation then. I reckon the best way to find out is to take a brick out and have a look!

[weeal]

Hi I think its been standard since 1990

[buildersmate]

There is nothing within Building Regulations that says that cavities must have insulation in them.
What is required is that the U-value of the walls is of a minimum standard. There are several ways to achieve this - one of which is to have the cavity insulated with polyurethane or similar types of foam. But there are other ways of doing it.
As you correctly say, minimum insulation standards for NEW houses has been increased progressively over the last few years. This has no bearing on the requirement for older properties.
But it is in every householder's interests to insulate their property, irrespective of what Building Regs might require as a minimum.

[dipee65]

Thanks Buildersmate. This reinforces my thoughts that the only way to be sure is to physically check - get a brick out. There s no evidence that insulation has been installed as a retro-fit.

[vivandorron]

I am fed-up with firms calling at my house with offers for cavity insulation.

In my opinion one saves very little on heating costs and the expenditure of putting it in takes many years to balance the books. Furthermore,one risks the possibility of dampness developing on internal walls because air can no longer ciculate within the wall's cavity and water penetrates through from outside by capilliary action as a result of bridging the gap between two walls......Ron

[buildersmate]

Sorry - don't agree Viva.
Companies providing such insulation products and installation service HAVE to check the external walls for exposure to the elements. In some situations foam installations are not permitted. Also the foam has to be a closed cell type so water does not go from one side to the other.
You assert that it doesn't save much - on what basic do you say this? Sure, it depends what else has been done already to insulate your house - if nothing done in the loft space then it's obvious that the best use of insulation is up there. But insulating cavities is now a standard part of new house construction - do you imagine Building Regs would permit this if it caused the type of problem you suggest?
Air does not circulate in the cavity. Full-stop. The purpose of the cavity is to form a water bridge to stop the damp in the outer cavity coming across to the inner.
If you have damp on the inside it is occuring because the inner wall is too cold (hence the need for insulation) and/or their is too much moisture from showers, clothes-washing etc.

[vivandorron]

buildersmate... I find it difficult to disagee with much of what you say but .What about dirty wall ties which cause no problem until the cavity is filled and then damp patches appear on the inside wall.?

[The Builder]

....................it's an old old argument this one Ron.............I agree completely with everything my Mate has said................Building Regs require cavities to be sealed.............for fire prevention reasons.........ie fire spreads quickly in a cavity.........just like going up a chimney.
The wall tie argument is a red herring...........as it were.......cavity fill doesn't cause a dirty tie to transfer damp. It's probably already there...............changing something eg having cavities filled, just draws your attention to it.

[vivandorron]

I respect everything that has been said by The Builder and his mate. However, whilst my loft is half boarded and fully insulated, I remain unconvinced that Cavity Insulation is a real necessity. What's wrong with the alternative of heat reflecting materials on inside walls?.

Apologies dipee65 if I have caused a distraction from your question. However, irrespective of my somewhat set views on cavity insulation, I acknowledge that the 'Building Boys' are more expert on matters than myself.

Best wishes all ........Ron

[dworkin]

Ron asked 'What's wrong with the alternative of heat reflecting materials on inside walls?.' and the obvious answer is that only radiant heat can be reflected.
In an average house very little heat transfer comes from radiant heat warming up walls. Its pretty much all conductive transfer from warm air to wall and thence to the world outside.