Internal wall insulation

sisteranna_2

I am a DIY novice and want to install insulation backed plasterboard to an internal (outside) wall of the Victorian house I've just bought. I've looked on the net, and there's so much information, I'm bogged down before I start - eg size of battens, dew point (!) vapour etc. There is a damp patch on the chimney breast, will that be a problem? We've had the roof done. I'd be very grateful for some practical advice, we need to do this as cheaply as possible, but also needs to be a good job too of course. Thank you.

zippychick

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Smiley_Dan

Assume the thread has been moved *here*.

There's a lot of conflicting advice on this. You're right to be mindful of condensation risk. It does require an attention to detail.

Take a look at http://www.greenspec.co.uk/building-design/internal-insulation/ and http://www.superhomes.org.uk/resources/internal-wall-insulation-1/ . I would advise posting at the Green Building Forum where there's far more expertise on this.

Definitely prefer sticking boards rather than studwork, unless the studwork has a second layer over the top to avoid bridges.

Definitely insulate the window reveals and remove cills and insulate.

edgex

I will be doing this this year, & have spent a fair time researching, & found Green Building Forum to be the most useful.


Basics;
Strip plaster off so back to bare brick
Fix insulation board to wall
Tape/seal all joins
Fix plasterboard over

Your aiming for a U-value of 0.5
Current walls will be approx 2.0

stator

It really is something that should be done by a qualified person :S

MisterBaxter

A DIYer can do internal wall insulation without any real problems with some caveats. External wall insulation is a whole different matter.

The fixing of the boards is easy, use insulation backed plaster boards, something along the lines of gyproc thermaline (get the best r-value you can afford) the manufacturer will pretty much tell you what to do but I would go with dot/dab supplemented by mechanical fixings. If the existing plaster is dry and sound then it can be left insitu but don't forget the boards are quite thick so will eat into your floor space. Finishing would be the same as for normal dry lining, the joints need to be sealed also, the junctions between wall/ceiling and corners.

Things to consider where relevant:-

Skirting boards and architraves will need to be removed and refitted.
Closing around the windows needs to be thought out.
Radiators/pipework needs to be moved.
Electrical sockets/light switches need to be extended.
Air bricks need to be maintained and the liner extended.
Generally the higher the R-Value the thicker the material so in small rooms there may have to be a compromise between performance and thickness (amount of space it will take up).

edgex

MisterBaxter wrote: »

A DIYer can do internal wall insulation without any real problems with some caveats. External wall insulation is a whole different matter.

The fixing of the boards is easy, use insulation backed plaster boards, something along the lines of gyproc thermaline (get the best r-value you can afford) the manufacturer will pretty much tell you what to do but I would go with dot/dab supplemented by mechanical fixings. If the existing plaster is dry and sound then it can be left insitu but don't forget the boards are quite thick so will eat into your floor space. Finishing would be the same as for normal dry lining, the joints need to be sealed also, the junctions between wall/ceiling and corners.


Generally the higher the R-Value the thicker the material so in small rooms there may have to be a compromise between performance and thickness (amount of space it will take up).

so not Gyproc Thermaline


30mm thick board of Thermaline has an R-value of 0.55
Thermal Conductivity: Basic expanded polystyrene 0.040W/mK

Celotex PL4000 (which is plasterboard + insulation)
28mm thick has an R-value of 0.70
Thermal Conductivity: 0.022 W/mK


higher R-value = better
lower thermal conductivity = better

MisterBaxter

Gyproc Thermaline starts at and R-Value 0.55 for 30mm at the other end of their range the Gyproc Thermaline Super starts at an R-Value of 1.97 for 50mm and 4.06 for 90mm; but it will come down to cost, needless to say the 90mm super is considerably more expensive than the basic 30mm boards but the range is wide enough to get something that suits the budget.

There are a number of other manufacturers that do thermal boarding so it really does come down to shopping around and looking for the best insulation at the price you want to pay. I'm sure I've seen some of the larger DIY outlets with their own branded stuff. The R-Value should be printed on the boards so you know what you're buying.

brightontraveller

I’d disagree with using gyproc etc

A better solution 99.% of the time is a Magnesium Board with an aerogel insulation
beats alternatives eg gyproc, cement etc insulation based boards in that its has higher or is more rot proof, fire retardant, smoke free, suppress flame development, non combustible, mold and mildew resistant (no bacterial platform for mould growth ) has high impact resistance, (can be used structurally) higher soundproofing qualities, less weight ,uses a fraction of space, better R-Values, Thermal Conductivity etc

If the above are not issue/ considerations then gyproc based solution if they are then don’t ? Mag board with aerogel !!!!es all over all its comparables

Mag and aero are used less because of ignorance and possibly cost ?:rotfl:

MisterBaxter

brightontraveller wrote: »

I’d disagree with using gyproc etc

A better solution 99.% of the time is a Magnesium Board with an aerogel insulation
beats alternatives eg gyproc, cement etc insulation based boards in that its has higher or is more rot proof, fire retardant, smoke free, suppress flame development, non combustible, mold and mildew resistant (no bacterial platform for mould growth ) has high impact resistance, (can be used structurally) higher soundproofing qualities, less weight ,uses a fraction of space, better R-Values, Thermal Conductivity etc

If the above are not issue/ considerations then gyproc based solution if they are then don’t ? Mag board with aerogel !!!!es all over all its comparables

Mag and aero are used less because of ignorance and possibly cost ?:rotfl:

Do you have actual experience with this stuff? We looked at it for a housing project that was grant funded but the energy savings didn't cover the scheme costs so it didn't go ahead. Never really revisited the stuff but may be worth another look.

How does it perform ano how do costs compare? (I'm assuming this is the stuff the sales rep has great pleasure in telling you about how it was developed by NASA)

sisteranna_2

Thank you everyone for your help, your information has certainly given me food for thought.