Batten size - drylining
- Thread starter FreeD
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FreeD
Private Member
Hi
Its to dryline internal wall on Victorian property...treated battens to wall...foil backed boards attached. Builder wants me to hack off to picture rail then dryline and patch in to picture rail...If i use 25mm battens I reckon the bottom will be proud of the top is it ok to go down to 18mm for example?
Its to dryline internal wall on Victorian property...treated battens to wall...foil backed boards attached. Builder wants me to hack off to picture rail then dryline and patch in to picture rail...If i use 25mm battens I reckon the bottom will be proud of the top is it ok to go down to 18mm for example?
Chris W
Well-Known Member
why cant you remove the picture rail, do the job properly with cellotex, batten over the top etc then stick the picture rail back over the top when youve done skimming?
that way you use concrete fixings to fix the batten to the wall through the cellotex, leaving no timber in contact with the wall, insulate the wall, eliminate the possibility of penetrating damp and condensation problems and you havent got the virtually impossible task of trying to make it look even half decent when youve done...
by the time youve hacked off around the picture rail it'll be loose, and nailed into timber blocks in the perps.. tease it off carefully and bobs yer uncle..
that way you use concrete fixings to fix the batten to the wall through the cellotex, leaving no timber in contact with the wall, insulate the wall, eliminate the possibility of penetrating damp and condensation problems and you havent got the virtually impossible task of trying to make it look even half decent when youve done...
by the time youve hacked off around the picture rail it'll be loose, and nailed into timber blocks in the perps.. tease it off carefully and bobs yer uncle..
FreeD
Private Member
Hi Chris
I totally agree with you...the builder is adamant for me to do it this way even though I have told him that the picture rail is likely to come away with the render anyway...think he is trying to save cost for the customer...
You say to use something behind the battens so they don't touch the wall what product would this be?
Whats the minimum total thickness i can get away with I only ask because I will have to keep coving in line.
I totally agree with you...the builder is adamant for me to do it this way even though I have told him that the picture rail is likely to come away with the render anyway...think he is trying to save cost for the customer...
You say to use something behind the battens so they don't touch the wall what product would this be?
Whats the minimum total thickness i can get away with I only ask because I will have to keep coving in line.
Chris W
Well-Known Member
you put cellotex behind the studs and butt the joints up, gaffer tape the joints and put the studs over the top of the cellotex..
youll never do it leaving the picture rail in situ though, be way off.. 75mm or so
or just use 18x38mm lath and 9mm board+ skim leaves you near enough 30mm..
but thats saying the picture rail is on 30mm of plaster?
if not might get away with tanking the wall then dabbing m.r. boards up?
or render it with waterproofer...
f'ck knows..
youll never do it leaving the picture rail in situ though, be way off.. 75mm or so
or just use 18x38mm lath and 9mm board+ skim leaves you near enough 30mm..
but thats saying the picture rail is on 30mm of plaster?
if not might get away with tanking the wall then dabbing m.r. boards up?
or render it with waterproofer...
f'ck knows..
FreeD
Private Member
Cheers Chris...not going to have the depth for insulation...I've been reading this and looks like it might be a waste of time without protecting against thermal bridges.
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Just wanted to let the walls breath...and ideally insulate if possible.
Decided I'm going to go with giving the customer option of standard dryline if picture rail is removed and depth will allow.
If not render with waterproofer with no guarantee
If he wants to protect against damp/salts/waterproof then I'll offer Vandex or Izonil etc
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Just wanted to let the walls breath...and ideally insulate if possible.
Decided I'm going to go with giving the customer option of standard dryline if picture rail is removed and depth will allow.
If not render with waterproofer with no guarantee
If he wants to protect against damp/salts/waterproof then I'll offer Vandex or Izonil etc
Chris W
Well-Known Member
eventually you'd get damp, only a lot slower than if you didnt use waterproofer..
point is, if theres any chance of leaky pipes, ground level too high all that then sort it first.. repoint any dodgy brickwork externally etc...
then, if its just a 9" solid wall with a dpc, render it above the dpc line with waterproofer and any water that gets in just by rain hitting it will dry out agian from the outside before it gets through the render...
it'll only come through the render if the bricks its on are absolutely saturated... the only way youll stop that happening is to tank the wall, then render it preferably....
but the easiest way is just to solve the problem, if there is one, and crack on...
put it like this.. if waterproofer made your wall 100% waterproofer you wouldnt need a salt repellant in the mix bacause the render would hold any water back, so the salts cant come out..
they use a 3:1 mix with waterproofer and salt repellant on damp jobs to keep the water thats already soaked into the wall from coming through the new plasterwork, but youre still not supposed to paint it for a year.. or at least use a breathable paint...
this builders insisting you use a foil back, theyre for vapour control, stopping water in the air inside permeating the board and coming into contact with the cold brickwork and condensing...
So, if its condensation you need ventilation, and possibly (much better) insulation..
if its penetrating damp, sort the problem and render it...
if its rising damp, see flynny.. :
point is, if theres any chance of leaky pipes, ground level too high all that then sort it first.. repoint any dodgy brickwork externally etc...
then, if its just a 9" solid wall with a dpc, render it above the dpc line with waterproofer and any water that gets in just by rain hitting it will dry out agian from the outside before it gets through the render...
it'll only come through the render if the bricks its on are absolutely saturated... the only way youll stop that happening is to tank the wall, then render it preferably....
but the easiest way is just to solve the problem, if there is one, and crack on...
put it like this.. if waterproofer made your wall 100% waterproofer you wouldnt need a salt repellant in the mix bacause the render would hold any water back, so the salts cant come out..
they use a 3:1 mix with waterproofer and salt repellant on damp jobs to keep the water thats already soaked into the wall from coming through the new plasterwork, but youre still not supposed to paint it for a year.. or at least use a breathable paint...
this builders insisting you use a foil back, theyre for vapour control, stopping water in the air inside permeating the board and coming into contact with the cold brickwork and condensing...
So, if its condensation you need ventilation, and possibly (much better) insulation..
if its penetrating damp, sort the problem and render it...
if its rising damp, see flynny.. :
FreeD
Private Member
Chris W said:
Thanks Chris. Do you mean on the inside with the above?
Would you say it was better to dryline Victorian properties...treated battens on wall with damp course behind...membrane then plasterboard.
There are no obvious sign of damp...I would have thought drylining was safer than rendering because the walls can breath and less likelyhood of salts coming through.
simple...
partition rooms.... use cls timber 3x2 or 4x2
with cls you can use upto 15mm plasterboard (soundblock, moisture resistant etc)
with metal stud work, maximum load is 12mm plasterboard
as for battening out, say ext wall (internal block work or similar etc)
depending on what insulation they want...
say 50mm kingspan. then you would use 2" battens (50mm)then board on top...
or dot and dab, thermaline boards (plasterboard & insulation together )
directly to the wall .. (if its post 1960's double skin wall)
do you all agree or what?
partition rooms.... use cls timber 3x2 or 4x2
with cls you can use upto 15mm plasterboard (soundblock, moisture resistant etc)
with metal stud work, maximum load is 12mm plasterboard
as for battening out, say ext wall (internal block work or similar etc)
depending on what insulation they want...
say 50mm kingspan. then you would use 2" battens (50mm)then board on top...
or dot and dab, thermaline boards (plasterboard & insulation together )
directly to the wall .. (if its post 1960's double skin wall)
do you all agree or what?
Chris W
Well-Known Member
Chris W said:
use 50x25 lath over the top, its got a thermal break, 25mm air gap, no blobs of dabbing,no timber touching the wall - treated or not, youve got somewhere to put your cables and if you gaffer tape the cellotex joints you dont need a separate vapour barrier..
As for 'victorian properties' in general, you treat whatever problem there is with whatever is the most suitable and cost effective method... its a damn site easier to insulate the walls internally than externally.. if you dont want to insulate it, just render it with waterproofer..
again, the vapour barrier is there to stop warm air in the room reaching a cold surface, thereby increasing the moisture problem.. whatever runs down your windows when your cooking is what will condense on a cold wall... which is why you get mould growth behind wardrobes on external walls due to the lack of heat and ventilation with the presence of moisture in the air (humidity), when it reaches its dew point (like when it hits a cold surface) it condenses into water... which is what mould grows on...
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