Cavity wall insulation

[wanderer]

Folks.
I'm considering getting the Walls of the house pumped to give if a bit more insulation. The house is 30yrs built but is very cold at present.
Has anyone had this done before? Is it a good job? The local installer is Erne insulation, has anyone had any dealings with them

[lawnseed]

Folks.
I'm considering getting the Walls of the house pumped to give if a bit more insulation. The house is 30yrs built but is very cold at present.
Has anyone had this done before? Is it a good job? The local installer is Erne insulation, has anyone had any dealings with them

wanderer there are alot of people getting this done. i'm in two minds about it, i'd be worried that the water that comes through your outside block would cross the cavity and end up in your inner wall. although i was told it doesnt happen but if it did you'd have to pull the wall down. i retro fitted a couple of the 'easier' rooms in my house with insulated plasterboard its a great job although the skimming up was a little bit messy. just do the exterior walls all you need is longer screws for your sockets and widen your window boards. you can do it yourself and get a plasterer to skim it up

[Windmill abu]

I have been working in the construction industry for just over 30 years. Back then fitting cavity wall insulation as you built was standard practice and getting walls pumped was only for older houses. Are you sure that there isn't already insulation in your house.

Pumped insulation is usually a good solution and is done from the exterior unless your house has a facing brick exterior which means it has do be done from the inside which causes more disruption.

We have found that most problems with loss of heat are down to windows and doors. No amount of cavity wall insulation will compensate for heat loss from poorly fitted windows and doors or lack of good double glazing to same.

[Tony Baloney]

You're always going to lose more heat through through a window than a cavity wall regardless of how well it is fitted. Can never have too much insulation so I'd follow lawnseeds advice.

[Minder]

You're always going to lose more heat through through a window than a cavity wall regardless of how well it is fitted. Can never have too much insulation so I'd follow lawnseeds advice.

Wowser 

[Tony Baloney]

You're always going to lose more heat through through a window than a cavity wall regardless of how well it is fitted. Can never have too much insulation so I'd follow lawnseeds advice.

Wowser 

Mark the calendar.

[mylestheslasher]

Lawnseed is right if you have a choice. However, the foam back slab is very intrusive if you are living in the house. If you have door frames near the outer wall for example it can get messy. The other thing is putting 50mm or more on the walls if the rooms are small will make them seem smaller, especially if there are 2 or more outer walls. I've seen a good few houses pump the cavity and there were no side effects but of course others may be right to say it can go badly

[ONeill]

Wear a hat. We've never been happier.

[Main Street]

Folks.
I'm considering getting the Walls of the house pumped to give if a bit more insulation. The house is 30yrs built but is very cold at present.
Has anyone had this done before? Is it a good job? The local installer is Erne insulation, has anyone had any dealings with them

The problem is moisture and it is a bigger issue than heat loss due to lack of insulation.
Basically the cavity construction deals with moisture and damp weather but not the cold.

Moisture comes in from outside and moisture leaves the inside to go outside.

The cavity is there for a purpose, moisture (from inside the house and from outside) goes through the wall and is dealt with by the space of circulating air in the cavity.
I have not come across one building issue which inspires so much confusion with the many variations of expert information offered. Not that I understand it, because the application of the principles, change according to weather conditions and type of construction and there are myriad of effects which result from attempts to make changes.

I used to have the problem of regular day to day moisture escaping from the living area, up through the ceiling & attic insulation, into a restricted attic space, freezing in frosty weather, moisture formed into ice on the roof joists and melted when temp rose, causing dripping water which would invariably come through light fittings,  pools of water on parquet floor.
That could have been sorted by a poly wrap but that would have required major construction surgery. It was simply solved by allowing wind into the attic space, so when the warm damp air enters from below into the the attic space, there is a gale of fresh air to deal with it.

If you understand what was happening in my situation, you can understand what deals with the damp process in a cavity wall.
The difficulty is, I could observe clearly what was happening in my attic but one cannot see what is happening inside a cavity wall.
The cavity is there to act as a moisture barrier by allowing air to circulate and deal with the moisture entering, both from outside and from inside the house. You should also have a number of air vents or some system to allow fresh air in to circulate around inside the cavity. If you remove that cavity by filling with insulation, then you are removing an effective moisture barrier.  The effects of doing that differ, depending on a number of variable.

Probably I would go for 4" insulation on the inside. It is more expensive process though.
And you need fresh air circulating around the house. A simple guide to that, is observe the moisture build up on the inside of windows.

[Orior]

Is that diagram from someone who sells cavity insulation or an independant?

I dont believe the percentages.

[mannix]

Bite the bullet and save in the long run, use the sheets of plasterboard with the insulation on the back of them, put them on the outside walls and insulate the attic to a high degree.it really works and you will kick yourself for not doing it earlier. If money is tight do one room at a time and finish that room out fully.my parents place was like an icebox even with the heat on , they have half the house done and it's unreal the difference between the rooms done and not done.

[ha ha derry]

Before you do anything, check that the insulation in your roof space is evenly distributed (leaving no gaps). When I moved into my house the guys fitting the tv ariel had pulled the insulation back to put in the cable and didn't put it back. Then check windows and doors for draughts. Fixing the above items will on its own make a huge diference. 

[mylestheslasher]

Bite the bullet and save in the long run, use the sheets of plasterboard with the insulation on the back of them, put them on the outside walls and insulate the attic to a high degree.it really works and you will kick yourself for not doing it earlier. If money is tight do one room at a time and finish that room out fully.my parents place was like an icebox even with the heat on , they have half the house done and it's unreal the difference between the rooms done and not done.

Did they batten the walls and then fix the boards or stick them on with plaster dabs?

I did neither. There are special "nails" you use, drill through the slab, insulation into the wall and beat the nail through. Put 8 or 9 in each slab.

[mannix]

Myles is bang on, rent or borrow an sds drill to drill the slab fixer holes. It easy enough to fit them. You will need a plasterer to skim coat the whole thing but well worth the time and effort.do not forget the ceilings, you can use a lighter insulated plasterboard on ceilings if you do not want to insulate the ceiling from above. In essence, what you are doing is blocking air from escaping.
Cavity insulation is not a patch on this method, you are heating block which soaks heat and cools a room as soon as the heat source is switched off.

[Tony Baloney]

Myles is bang on, rent or borrow an sds drill to drill the slab fixer holes. It easy enough to fit them. You will need a plasterer to skim coat the whole thing but well worth the time and effort.do not forget the ceilings, you can use a lighter insulated plasterboard on ceilings if you do not want to insulate the ceiling from above. In essence, what you are doing is blocking air from escaping.
Cavity insulation is not a patch on this method, you are heating block which soaks heat and cools a room as soon as the heat source is switched off.

This is all well and good but you need to have ventilation in a house too. It's not healthy to live in a hermetically sealed box!