Dry lining one or two walls

[catfordbags]

I've given up on insulating the cavity walls. The 5th surveyor in a row has told me it can't be done (cavity too narrow 30mm and too dirty) so I think i'm starting to believe them.

I haven't got the time or energy to put internal insulation throughout the house but there are a couple rooms which have nice square walls with no windows and these seem an easy win so i'm think of dry lining (?).  Is this a sensible plan of attack or is there issues when only insulated a couple of walls ? 

[guydewdney]

You can get 'drylining' with insulation on the back. Also consider - if appropriate - external cladding insulation.

[JohnS]

I am in the process of drylining/ internal wall insulation my house with solid 9 in brick walls with lime mortar.

My method depends on whether the plaster is in good condition or is blown.  If blown I hack it off the wall but if good I leave it.  Also I hack off if space is critical in the room.

I then stick 50mm kingspan to the walls with adhesive foam.  Tape joints.  I then fix with 25mm battens where needed.  I fill in between the battens with 25mm kingspan.  I then fix 10mm Fermacell, either using their joint stick adhesive between panels of leaving a gap and using their filler.  The Fermacell is screwed to the wodden battens.

The Fermacell can be either skimmed with their fine surface treatment or just painted.  A couple of layers of emulsion does fine and looks nice and smooth.  Fermacell is much stronger than plasterboard for hanging pictures etc, although I make sure that there are battens behind the radiators.

John

[biff]

hi cat,
      john and guys methods will work well.dry lining has always been a prefered option in such cases.a point of intrest it that you do not have to do the whole house in one run,you can do a room at a time,get that particular exterior wall finished and decorated before moving on to the next one as your pocket and expertise sees fit.the more you do,the more experienced you will become so by the time you get to windows and doors you will figure out how to give nice square edges on the reveals.you will notice the difference in each room immediatly.
                                                                                                 biff

[EccentricAnomaly]

Presumably internal insulation like this will make lifting the floorboards more awkward and/or messy. Would it, therefore, be a good idea to see to any airtightness/insulation under the floor first?

[JohnS]

EA

You are correct.  I had already insulated under the floor of the downstairs room that I have IWI'd.  Upstairs is not such an issue, although I put rockwool in between the joist and the wall and for a foot at the end of the joists on the adjacent side.  It was easy as I was reflooring at the same time.

John

[Iain]

Hi
I have solid brick walls, end terrace. lime morter. As I don't want to replaster all the walls, I have just done the alcoves in all the rooms against the end (gable end wall) I just used the 40mm version of this
:- http://www.british-gypsum.com/products/plasterboard___accessories/gyproc_thermal/gyproc_thermaline_plus.aspx

Even though only the alcoves have been done the difference has been remarkable. I suppose the chimney breasts are "cavity" anyway. This has been a very effective compromise.
Iain

[Mike McMillan]

I too had a problem with my cavity wall. By the end of last November, we were so cold, that I drove north to the silva pearl factory and loaded 100 bags of the stuff into a van. I then "blew" it into the roof void and into the cavity wall with a leaf blower. B.... dusty, but the difference has been truly amazing!

Mike McMillan

IOW

[JohnS]

Mike,

What was the product that you bought?  Vermiculite? Silvapor? Perlite? etc  There seem to be so many similar ones all of different grades.

Does the factory sell direct?  About £17 per 100l is the best I can see on the net.

John

[chasfromnorfolk]

Dot and dab is tricky to get right. If your ceiling height is 8 feet or less and there is no inherent damp problem then 50x50 tanalised  (notched for the skirting) fixed with big screws and rawlplugs or frame fixings at 400mm centres, filled between with 50mm Cellotex and covered with 12.5 tapered edge plasterboard will improve things. If the ceiling is more than 8 foot (ok, 2400) you can still avoid horizontal and taperless jointing if you raise the boards up the six inches hidden by the skirting and use odd pieces down there. If the ceiling's more than 8'6" and you're plastering's suspect, you have a problem. Otherwise the making good on the tapered joins is not too bad.

Chas

[catfordbags]

What i've heard is that there are possible issues with some walls being dry lined and others not. IE - some warm walls and some cold walls - and possible condensation ?

Any ideas if this is likely to be a problem or not ?

[Mike McMillan]

i John,

It was Silva Perl. The factory were very helpful and I seem to remember it was £9 a bag.. Hang on, I'll look in my diary. £6.60 a bag, plus vat. I think they wanted £14 a bag here at Jewsons. I hired a ford transit and drove up through the snow. I couldn't quite get 100 bags in, 96 (including some in the front). Probably with a little more time to stow, I could have got them all in, but it was chucking it down and half the country was at a standstill. Just made it back!

Mike

http://www.william-sinclair.co.uk

[catfordbags]

i John,

It was Silva Perl. The factory were very helpful and I seem to remember it was £9 a bag.. Hang on, I'll look in my diary. £6.60 a bag, plus vat. I think they wanted £14 a bag here at Jewsons. I hired a ford transit and drove up through the snow. I couldn't quite get 100 bags in, 96 (including some in the front). Probably with a little more time to stow, I could have got them all in, but it was chucking it down and half the country was at a standstill. Just made it back!

Mike

http://www.william-sinclair.co.uk

Mike - maybe this stuff is what i'm after. What was the problem the problem with your cavity ? Do you know the width of it. I think mine is only 30mm wide and the professionals won't do it under 50mm. And do you know if there are issues around damp and cold bridges etc using Silva perl ?

[wookey]

EA the best way to avoid the floor problem is cut back floorboards at edge and continue insulation through the floor. This has huge airtightness benefits and will make the insulation a lot more effective. It's important to get airtightness detailing round the joists right.

JohnS's build details are good, althogh I'd make more emphasis of taking great care to have a continuous vapour barrier at all joints.

[Mike McMillan]

I've had no problems with that. I guess there must be some voids under the windows, but the stuff is extremely slippery. It was the filthiest job I have ever undertaken, but I was blowing it in with a leaf blower. If you have room to tip the sacks in, would be much easier. You will quickly find out if you have any holes anywhere as it will flow out unchecked! You will still need goggles and mask, it is dusty as hell, but does the job. Give them a ring, very friendly. I am experimenting at the moment, mixing it up with cement and sand to see if I can make an insulated mix to pour on the flat roof!

Mike