DIY - Drylining bedroom walls

kopkidda

Was thinking of doing this job myself, looking at putting insulation board to existing external bedroom wall, is this a feasible diy project, I'm fairly competent with DIY.

stiofan85

kopkidda wrote: »

Was thinking of doing this job myself, looking at putting insulation board to existing external bedroom wall, is this a feasible diy project, I'm fairly competent with DIY.

I did it recently and found it okay to do but I think you need to do your research in terms of moisture movement and potential for condensation/mold growth behind the insulation if you do it yourself.

My understanding is that you need to prevent air getting behind the boards for a fire stop and preventing mold.I used plasterboard adhesive and ensured a continuous line of adhesive around the edge of the boards and then crossed it a couple of times across to create separate areas behind the boards to ensure any air that did get through was prevented going further. I removed all wallpaper from the wall to ensure better adhesion and prevent any organic material being a growing environment for mold. (see pages 6/7 here: http://www.xtratherm.com/wp-content/themes/xtra/downloads/publications/Xtratherm_UK_Drylining_Guide_11_3.pdf)

Then I used mechanical fixings as in a fire the foam on the back could melt off and the plasterboard could then fall over and block the path of/injure a firefighter.

Other thing to consider is raising the boards off the floor with a length of 2x1 and once set, fill the gap with expanding foam top and bottom to ensure air can't get behind the boards.

I found it hard to get the boards perfectly square due to the wall behind not being straight.

Also take into consideration purchasing and transporting the boards.

When it came to getting a BER the assessor didn't take the insulation into account because despite having the offcuts and photos of the insulation going on the walls, I had lost the receipts and so could not prove the exact materials I had used.

This is just my experience of doing it from an average Joe point of view.

kopkidda

That's great info, thanks for taken the time to tell me your experience..

dok_golf

Open to correction here but you might also have to put a moisture membrane behind the new plasterboard.

stiofan85

dok_golf wrote: »

Open to correction here but you might also have to put a moisture membrane behind the new plasterboard.

I used insulated pb with the vapour barrier included. Per my original post I think it's important to research the implications for moisture movement if taking it on DIY as mold is not something you want festering unseen.

kopkidda

So am I correct in saying that you put the insulation board direct onto the current internal wall, secure and then plasterboard on top and then plaster?

SemperFidelis

You can get plasterboard with the insulation already attached. Attach this to the wall and then plaster over the joints, sand and paint.

kopkidda

SemperFidelis wrote: »

You can get plasterboard with the insulation already attached. Attach this to the wall and then plaster over the joints, sand and paint.

Simple as that , whats all this talk about moisture moving around?how do I attach platerboard with insulation to current wall?

stiofan85

kopkidda wrote: »

Simple as that , whats all this talk about moisture moving around?how do I attach platerboard with insulation to current wall?

if moisture can get behind the insulation, it will be much colder there than in the bedroom and it will condense, which can cause mold on the wall and will be unseen behind the insulation. Mold can cause breathing problems, so my point above was to make sure you do your homework on it to ensure you don't end up with mold.

Check out this page: http://www.josephlittlearchitects.com/articles/breaking-mould-1-study-condensation-single-leaf-concrete-wall-upgrades

kopkidda

stiofan85 wrote: »

if moisture can get behind the insulation, it will be much colder there than in the bedroom and it will condense, which can cause mold on the wall and will be unseen behind the insulation. Mold can cause breathing problems, so my point above was to make sure you do your homework on it to ensure you don't end up with mold.

Check out this page: http://www.josephlittlearchitects.com/articles/breaking-mould-1-study-condensation-single-leaf-concrete-wall-upgrades

Ye good point, the walls that i'm thinking of insulating have no problems with moisture or mold so should be alright.

SemperFidelis

I used this stuff on 50mm boards as its done here;

https://www.youtube.com/watch?v=3CJygvnajUA

Mmmm_Lemony

SemperFidelis wrote: »

I used this stuff on 50mm boards as its done here;

https://www.youtube.com/watch?v=3CJygvnajUA

Think this is what I'm looking for. What fixings did you use to attach to the wall? We have a very similar situation as above. Cavity walls, but very cold and history of damp patches. Worried without air tight barrier will fester behind the plaster.

SemperFidelis

I did two bedrooms with just the foam glue, line around the edge and then lines across the board every 300mm. One of the bedrooms was 4 years ago and still holding.

I recently did my kitchen but for it I used some of the mushroom fixings to hold the boards in place while the foam set so I could move onto the next board one more quickly. Especially useful on the boards above the windows.

Mmmm_Lemony

SemperFidelis wrote: »

I did two bedrooms with just the foam glue, line around the edge and then lines across the board every 300mm. One of the bedrooms was 4 years ago and still holding.

I recently did my kitchen but for it I used some of the mushroom fixings to hold the boards in place while the foam set so I could move onto the next board one more quickly. Especially useful on the boards above the windows.

Have you any recommendations for the foam glue and applicator? I'm planning on using mushrooms but want belt and braces if I can. I've already tanked the worst affected parts of the wall. Purely for water and air tightness, would tech 7 or similar provide the same functional properties as a foam glue?

kopkidda

Cheers for all replies, so going by that youtube video, you just apply the foam glue with applicator around insulated board, attach to current wall with fixings and that's is, very doable.

SemperFidelis

Yeh, just apply the foam. wait 5 mins. then push up against wall and hold for 2 minutes. Then throw in some mushrooms.


Then you have to plaster the joints, checkout a few videos on youtube to get a better idea how to do it.


This guy has some good videos, even uses coloured plaster so you can see easier;

https://www.youtube.com/watch?v=YII-NjA5dMQ

kopkidda

SemperFidelis wrote: »

Yeh, just apply the foam. wait 5 mins. then push up against wall and hold for 2 minutes. Then throw in some mushrooms.


Then you have to plaster the joints, checkout a few videos on youtube to get a better idea how to do it.


This guy has some good videos, even uses coloured plaster so you can see easier;

https://www.youtube.com/watch?v=YII-NjA5dMQ

And the mushrooms fixings, just go straight through the drywall and into the current wall, they don't have to go into a stud on the current wall?

SemperFidelis

yes, I think it was an 8mm hole through the plasterboard, insulation and into the blocks. Then hammer the mushroom in until the head is slightly below the level of the plasterboard so you can plaster over it.