home insulation question..

[Coolmist]

Hi

Ok so last winter I felt like i was freezing my bollocks off in the house with the heating ON..

This year I replaced the windows and pretty soon afterwards I realised that it has made a bit of a difference but its still pretty cold..

Now my home is circa 1995 build, it has cavity walls, brick-cavity-breeze block-plasterboard and the walls are very cold to the touch, some more than others, there is no internal insulation in these walls like there should be in the building spec

i looked at cavity wall filling but it seems that there are two camps..people that think its a great idea and the other people that are having it removed because it has caused a lot of damp

so the other day after trying to decide weather to have the cavitys filled with insulation i wondered why i havent seen anyone fill the void between the plasterboard and the breezeblock with insulation foam?

so i tried it on one small wall in the downstairs toilet...i drilled a hole through the plasterboard until i hit breezeblock then i inserted a bottle of expanding foam and dumped 50% of it in there

the wall is warmer in that area..you can literally feel the difference, i cant see how this would cause any damp as it is after the cavity and if any water could get into that part of the house then maybe i would have more serious problems than cold walls?

i am very tempted to buy a few more bottles on the way home and finish off the job at least in that room but have i overlooked something?, why do people not do this when its mega cheap and very quick (more so for me as i am about to decorate that room so can cover any holes)

advice/thoughts please?

[Nemesis]

Oh how the mighty have fallen!

Old Brian used to come on MIG as a hero, and throw 500bhp nitrous shots into his Calibra turbo.

New Brian bought a Datsun, and now only posts to complain about the cold!!!

I miss old TFS

Get a new sweater

[MSG]

would it not be cheaper to insulate your bollacks instead?

[Benn]

I cant see why it would be bad, all new homes have the foam like sheets stuffed in there.

I've seen a few older houses that have had the gaps filled with the foam balls you get in bean bags.. Ment to be very good too.

[jamied]

by insulating the cavity between your plaster board and breeze block you might cause more damp to start eating away at the plasterboard protective surface causing not only a nasty smell but sometime fungle rot.
Best get a quote for cavity wall insulation and also making sure you have the right heating set-up in your house.
Also type of flooring is a huge problem.

[king nero]

MIG performance home owners association

I want a knitting section!

[wayne451]

Bloody hell. I wondered where you had vanished to?

If you are cold with the heating on are you sure that the rads/boiler combination are sufficient for the rooms? There are many simple calculations you can do to confirm it - google is your friend 'BTU calculator'.

Why not use expanding foam? I do not know, I could only speculate but I would be tempted to let some set and expose it to water/humid conditions and see what happens to it.

People are always going on about loft insulation and all the rest of it but one of the most commonly overlooked things I experience is that people try to stop heat loss through the attic but they do nothing to stop it rising between ground and first floors etc. Attic insulation is also normally the lazy option rather than packing it down, it's just a half arsed roll out job.

Honestly, get the floor boards up and pack it up insulation between all floors - note the difference in ratings (R ratings). Lag pipes as it helps them retain heat and improves the systems efficiency. Stick those cheap reflective things behind your radiators. Get heavy curtains and tuck them behind the rads. Also, if you are decorating any rooms shortly there are modern insulative wallpapers and lining papers available which are about 5mm thick, also an abundance of insulative paint - honestly!

If you get both gas and electric from British Gas you can (or could) get either free loft or cavity wall insulation.

I hope that helps.

[Dom]

I had exactly the same dilemna - I'm with British Gas and they offered me free insulation so after a lot of research I took them up on it.

House is not any warmer - I didn't expect it to be as I've not turned up the heating ! It does however retain the heat for a lot longer - yesterday it was 5 degrees outside, the heating went off at 10am, the house was 20 degrees C and when I turned it back on at 4pm the house was still at just over 17 degrees C.

There is a huge increase in condensation - this is probably due to the fact the house no longer has all the draughts it had before the insulation - I use a portable dehumidifier for a couple of hours a day to keep this in check.

Only had it done for a month so can't comment on long term damp problems but if asked if I'd do it again I'd still be 50/50 lmao.

[Coolmist]

by insulating the cavity between your plaster board and breeze block you might cause more damp to start eating away at the plasterboard protective surface causing not only a nasty smell but sometime fungle rot.
Best get a quote for cavity wall insulation and also making sure you have the right heating set-up in your house.
Also type of flooring is a huge problem.

well i wondered about this but surely if i have moisture getting through the brick then the cavity and then the breezeblock then i have bigger problems?

the insulation is normally fitted in the cavity which can sometimes cause moisure to travel between the brick and the breezeblock and manifest itself onto the plasterboard which leaves damp spots...many people fit kingspan before they fit the plasterboard with no ill effects but what i have done is slightly different#? and a lot cheaper

the floor is concrete, no floorboards but this does not seem to be cold...its just the walls themselves

as for the datsun...she has gone...i have a rather nice CL500 now and everyone thinks im rich lol, no nitrous but i do have a sneaky turbo car in my garage...watch the projects section for more infomationz

[Violet]

I had a terrible problem with damp in the winter, it was building up on the ground floor where, for eg, a sofa was against the wall and in 'part of building' cupboards. There would literally be drips on the top of the wall in the cupboard. The house was also freezing, even in the summer, as it was in the shadow of the house next door and never got any sun.
I moved out, I couldn't take it anymore.

[Dom]

I had a terrible problem with damp in the winter, it was building up on the ground floor where, for eg, a sofa was against the wall and in 'part of building' cupboards. There would literally be drips on the top of the wall in the cupboard. The house was also freezing, even in the summer, as it was in the shadow of the house next door and never got any sun.
I moved out, I couldn't take it anymore.

Was this caused by Cavity Wall insulation though or just generally cold walls ?

[Giles]

Are you sure you dont have cavity insulation in your 1995 house? This would be very unusual.
You'll be most likely looking for a polystyrene sheet insulation in teh acvity held with brick ties to keep it away from teh external wall and so prevent water transfer.

Yes you can insulate between platerboard and the inner skin. It's the void between teh outer skin and inner that provides your segregation.
Quastion though - is the cavity there as it is a plasterboard on batten arrangement? If so it woudl be an odd design if that void was not there in order to be filled with insulation anyway (instead of cavity fill).


Re retro fit cavity insulation - the systems used (and method) do not promote damp penetration. Get a reputable company (or a few) round to quote (free) and explain how it works.

You say teh double glazing was retro fitted - does it have trickle vents? No cold bridging?

You need air changes in houses to avoid condensation as any cold surface will promote condensation. If you don't have them your best bet is to leave a top light open the first (vent) notch during the day, and close about 3pm so it can heat up in the evening.


As I think Wayne said -reflective material behind the rads increases efficiency of teh heating system you have.
Effective roof insulation (270mm I think is teh current thinking - can be less if using materials with better properties).
Wall insulation.
Floor insulation.
Blinds behind curtains improves insulation.
Thick curtains.
Curtains to hang BEHIND rads.


Afraid if it's a 'Barrett' type home you prooably only have the minimum of everything anyway so best check.

Oh - heating system - as wayne said check cacls to show if it is adequate.
Also I woudl strongly suggest some web surfing and then go and re-commission your rads. No doubt over teh years people have played with the valves and it's now unabalanced.
Easy job to do and usually worth it.

[Coolmist]

yep pretty sure!, upstairs we done some pretty major works and never found anything there, the internal walls however are stuffed with fibreglass type insulation

its a barrett type home, i have the building spec and its all ticked for insulation but there is none...

the plasterboard is fitted in places with battons but the majority we found is fitted by throwing a "splat" of something on the breezeblock and then pushing the plasterboard up against it until the splat stuff is dry, i seriously doubt that this is the correct way to fit the plasterboard...

i have changed every radiator in the house and the windows, in the frontroom i went from 2 mid size rads to 2 large double rads...well over double the area but still it is not enough..

the windows have vents in which can be closed, i have never had them open because there is no issues with condensation because the house is so cold lol

rads have been setup by myself, most of the time all rads in the house are off apart from the frontroom TBH

thanks for you input giles

[Giles]

Actually fixing plasterboard with dabs (splat) is a perfectly normal and excepted method. But yes - does feel a little shonky.

You balanced teh rads when you did them? And you'll need to do them all as you have changed teh dynamics of teh system. Also you will need to check (I'm sure you did) that the boiler and pumps coudl actually cope with teh extra flow and heat requirements, otherwise you could potentially make things colder.

You say you have set up the rads. DO you mean you balanced all teh heating system properlly and fully?
If not then Google the process. It's easy. Involves turning on heating and taking temps from the flow and return of each rad starting at the one closest the boiler and adjusting teh lock sheidl valves to get teh right temp drop accross each. If you don't do this for all rads you can find a huge rad can actually put out less heat than a small rad.
Good excuse to use you no contact thermometer.

The inetrnal walls are stuffed not for heat insulation but to reduce noise transfer. I'd be surprised if they did this but still no wall insulation anywhere.

I woudl be inclinded to get a specialist in for some free quotes.
Obviously you'll need to bear in mind the sales bollocks, but they coudl give you some interesting info as tehy will have experiance of your type of house, and how it was built and works.

Sorry for not being able to give you firm answers. But I think your best bet is to get someone tehre to actually look at your property and advise.

[MSG]

I live in 1930 solid bricks, gets quite cold especially the rooms that do not adjoin the neighbouring terraces, usually the back rooms, there is no way of installing cavity insulation, however, there are materials available which can be applied to the external exposed walls which is practiacally glued on, and is around 2 to 3" thick and insulates solid walls quite well, it is then finished with a final coat of dedicated paint to hide any joints etc, almost like a thin layer of skim. I might be getting this done depending on the cost.

However, over the years I have found that it does not pay to use timed heating, instead I run my winter heating 24/7 but what I do is reduce the boiler flow temeprature from around 50 degrees to just 30 degrees during the night, this mainatains warmth and does not allow the house to go completely cold, for instance it will bring the internal temeperature from 21 degrees to 18 when running at low flow temeprature, and 18 is still considerably comfirtable, and when your house remains warm throughout, you do not get any condensation problems, except on windows, even on double galazed windows some condensation occurs, but none on my walls or behind furniture.

The heating bills are no bigger than those who turn their heating on full blast but timed, i.e many people use a timer to switch their heating on for 2 hours in the morning and may be 4 hours in the eveneing, i.e. before getting up and leaving home for work and then the timer switches the heating on an hour before you return from work. This I beleive is a waste of time and requires the same amount of energy if you were running your heating constantly at a lower flow temeperature, so that means the room thermostate never needs cut in as the lower flow temeperature cannot heat the house beyon say 22 or 23 degrees, so we usually leave our room thermostate to around 25 degrees and allow the flow temeperature to maiantain a steady constant heat around 20 to 21 degrees, and the bills are still reasonable and no higher than the neighbours who cycle their houses through hot and cold cycles, this could also cause thermal stresses on things as they expand and contaract two times a day, mine stays constantly warm and no damp problems.

One reason I can't use a timer is because i work from home and spend most of my time stuck inside, so I need constant heating.

Why not try it? all you need is to take your meter reading when using the heating on a timer but with your usual higher boiler flow temeperatures, many people run theirs at around 70 degrees flow temeprature, that is a risk to children getting burned by radiators!

So try using my method, your boiler must have a dial to reduce the flow temeprature right down to around 30 degrees flow temp. and increase it to 40 or 50 when the day starts, and leave it there till you want to go to bed. Compare the meter reading to see how much gas you have used with each method, you will be surprised, but i can't guarantee that it can work for all houses and all boilers.

The only disadvantage being that the boiler flow circulating pump must run constantly, and thus may have a reduced life through wear, but that is not a real problem getting a replacement pump for around £35 to £50. and it adds to the cost of electyricity as it draws around 40 watts constantly. That works out 40x24=960watts or nearly 1kw per day or 10p per day extra for electricity! No big sweat.

[Dom]

My house is around the same age as T.F.S - I think mine was build in 1994.

Brick -> uninsulated cavity -> thermal block -> dot and dab -> plasterboard.

Plasterboard fixing with dot and dab is a very common (and correct) way of fixing it up - its a bloody nightmare to replace though as the adhesive sets rock solid !



You'll find you stop a lot of the draughts by having the cavitys insulated on these kinds of houses - they are thrown up in a hurry and little attention is paid to the quality of the worksmanship behind the plasterboard - my ensuite had a whole piece of blockwork missing where it was obviously too much like hard work trying to fit it in and I could get my whole arm out of the hole they left between the ensuite ceiling roof space and outside (we had loads of birds nesting). I could stand in the ensuite and poke my arm out and wave to the neighbours ......

[Giles]

Programmable heating clocks are the most efficient. And using a 'set back' heating strategy is proven to be the most cost effective (ie reduce temps when the building is not in use, and over night). As MSG says - to cycle heat from ambient to 'warm' during the winter requires more fuel and you have the inconvienance of a longer wait for a comfortable environment.

I would however say this is based on a well insulated building.
Therefore sorting your insulation is really still the key to all this.

Dom - no surprise. House builders are the funking cowboys of the construction industry. Little QA control and monitoring during construction (usually none by an independant party) and as it's all about a race to realise an investment so time is far more important than quality.
Additionally subbies are paid on piece work and so the quicker a wall is up the greater £ per hour they are making.

[Violet]

Was this caused by Cavity Wall insulation though or just generally cold walls ?

Just cold walls - It was rented, and I had someone check who said I should cover the outer and inner walls with polystyrene panels. That would've looked awesome. In one corner, the plaster had come off the wall and the brickwork was exposed, there was mould buildup, etc, and in cupboards, everything had to be moved out, you couldn't store anything in there. You couldn't keep on top of it so I got out of there.

You'll find you stop a lot of the draughts by having the cavitys insulated on these kinds of houses - they are thrown up in a hurry and little attention is paid to the quality of the worksmanship behind the plasterboard - my ensuite had a whole piece of blockwork missing where it was obviously too much like hard work trying to fit it in and I could get my whole arm out of the hole they left between the ensuite ceiling roof space and outside (we had loads of birds nesting). I could stand in the ensuite and poke my arm out and wave to the neighbours ......

I've seen that before, some people shouldn't be allowed near a lego set, never mind a building site.

[Astra Dan]

Interesting thread. I have asked before for a DIY section after I did the diary of replacing my bathroom floor. I think response was quite positive.

My house is mid 1920s with all the major boxes ticked - thick loft insulation, cavity wall insulation, double glazing and central heating with rads in all rooms and controlled by a fully programmable temp/ timer thingy. I recently moved from having the heating 'on' and 'off' (in reality a min of 19 degs then about 6 during the day/ night) up to a minimum of 16 degs during the day and night and I got a £200 refund from the gas supplier last year!

My main problem is the windows literally pour with condensation - can't really see out of the lounge windows at all; this is generally the warmest room obviously. I'm thinking it's a combination of fairly good insulation - i.e no drafts and high temp. differentials between the walls and suspended floors above damp earth. Or maybe crap windows.

[Ed]

Just put another jumper on.

Seriously though I fitted my own central heating and combi boiler to my double glazed concrete floored 1960s maisonette with no cavity wall insulation. I don't often have the heating on to be honest (combination of being tight and naturally liking a cool house). When I do put it on though the rooms gets roasting as long as I have the doors shut, and I can only bear it for an hour or so before I have to switch it off. The house then stays warm for hours.

The front door is wooden and not one of these UPVC jobs; it is very drafty but I think it helps dry the place out, as I never have any condensation issues. Bathroom window is also always open.

There's a lot to be said for getting a good draft going through a house I'd say lol. As long as you can isolate yourself in a warm lounge, and then air it out at night. I never have the bedroom rads on though; thick duvet and sharing body heat seems to be enough for a cold night IMHO. Even then I can get a bit of condensation on the windows in the morning. Leave the bedroom doors open though, and the drafty hallway soon clears that lol.

[MSG]

Good call mate for a DIY thread. left my boiler flow temperature at the minimum for most of the day today, only just turned it up to mark 3 now, It can be set between 1 and 9) and it is a Vaillant boiler about 15 years old, had it fully serviced earlier this year.

Anway, talking of the heating senario today, the boiler was set at lowest flow temperature of around 30 - 35 degrees since last night, and the ambient temeprature throughout my house was around 18 degrees till now, quite bearable, but I just turned it up now to mark 3 which increases the flow temeperature to around 45 degrees, and this should bring the ambient to around 21 degrees in about 2 to 3 hours, and will remain there until about 1 am which is about 2 hours before I retire to bed around 3 am.

I am constantly monitoring the energy usage, since now it is even more important due to high cost of gas to not waste it and use it most effectively, and I found that this method suits me better as I mostly at home.



Edit. As for Ed, thats what the poor old folks have to do, and I have had my leather jacket on most of the day.

[Ed]

Seriously, if I was struggling to pay the bills like so many seem to complain about, I would never have the heating on and just sit in a jumper and coat with the cat on my lap. Big deal! Heating your immediate vicinity (i.e. insulating your body) as opposed to heating an entire room, is much more effecient and effective. OK, so you can't sit there watching tele in your T-shirt and shorts.....get over it.

Or exercise, you soon get so hot that you find yourself stripping off. I was outside all day today digging foundations for my mates outhouse; I was down to a t-shirt for most of the day.

[DarrenH]

would you (anyone that knows) say that having loft insulation and then boarding over the top (chipped loft boards or normal floor boards) is beneficial ?

another question, if you already have loft insulation between the horizontal roof joists, is there any point or benefit of insulating the similar space between the truss/rafters ?

[*BenH*]

Your rafters are better off in free air so they dont get damp, as depending on the liner behind the tiles moisture may/will get though. If you loft insulation is only up to the top of the joist (for boarding over) you probley dont have enough really. I have for people made a island for storage above the joists so you can have deep insulation.

[wayne451]

Interesting thread. I have asked before for a DIY section after I did the diary of replacing my bathroom floor. I think response was quite positive.

Do it Dan. You've got the power!