waterproof plasterboard

[jono2000]

i've got to repair a flat heavily damaged by a leaking flat roof, the top half of the plasterboard is ruined, needs replacing.

IN addition to fixing the roof I've got a quote from the roofer stating he's going to use a "special waterproof plasterboard" system to do remedial work in the affected rooms.

does anyone know what this may be?

what would the experts recommendation be for replacing this area. my instinct is to assume the roof will be fixed, therefore just use normal plasterboard for the remedial work.

his "special waterproof" system is quite expensive and in these credit crunched times...

i think the problem may be that the wall is so wet that any new plasterboard will go the way of the old rotted stuff.

Untitled

• jono2000
• 8 Mar 2010
• 1

Untitled

• jono2000
• 8 Mar 2010
• 1

now thats damp.

 

[trowelmonkey1]

he can only be talking about tilebacker/aquapanel i suppose, but like you say, if the roof is fixed he doesn't need to use this, far from conventional, only used in bathrooms normally, and yes, very pricey compared to standard wallboard.

 

[NickB_99]

i've got to repair a flat heavily damaged by a leaking flat roof, the top half of the plasterboard is ruined, needs replacing.

IN addition to fixing the roof I've got a quote from the roofer stating he's going to use a "special waterproof plasterboard" system to do remedial work in the affected rooms.

does anyone know what this may be?

...

my instinct is to assume the roof will be fixed, therefore just use normal plasterboard for the remedial work.

his "special waterproof" system is quite expensive and in these credit crunched times...

i think the problem may be that the wall is so wet that any new plasterboard will go the way of the old rotted stuff.

I would hope he doesn't mean the green Moisture Resistant board

Not a pro, but surely if roofer is confident roof is fixed (+some time to dry out) then normal board should be ok after that. It's not a bathroom area!

 

[NickB_99]

Sorry TM1 - hadn't seen your reply before I started typing!

 

[Richard C]

IN addition to fixing the roof I've got a quote from the roofer stating he's going to use a "special waterproof plasterboard" system to do remedial work in the affected rooms.
does anyone know what this may be?

There is Moisture Resistant plasterboard, Duplex (foil back) plasterboard, vapor barrier plasterboard & water proof boards but no such thing as waterproof plasterboard; get (considerably) more details of what he is proposing & post back.

what would the experts recommendation be for replacing this area. my instinct is to assume the roof will be fixed, therefore just use normal plasterboard for the remedial work.
his "special waterproof" system is quite expensive and in these credit crunched times...

I would use Duplex board as a minimum but don’t know what else he is planning; it’s not much more expensive, couple of quid or so a sheet.

i think the problem may be that the wall is so wet that any new plasterboard will go the way of the old rotted stuff. now thats damp.

You cant do anything until the roof is repaired & it’s dried out &, from here, that looks like it’s going to have to come off or down & re-done, depending on weather it’s a base plaster finish or plasterboard.

 

[jono2000]

thanks for speed replys guys.

yes it needs to come down, its a steel frame and blockwork building apparently, there seems to be an estimate of around 12-18months for the whole thing to dry out properly, hence the option of using this "special waterproof" system. not sure if its membraned or not.

would i be better with DUPLEX or should I go for the fireline MR (ie moisture resitant?)

 

[Richard C]

would i be better with DUPLEX or should I go for the fireline MR (ie moisture resitant?)

Why Fireline?

 

[jono2000]

why fireline - it doesn't have to be fire retardant - its the next one in the listing of plasterboards on the british gypsum site, DUPLEX is in with the fire retardant section and I wondered if Fireline MR was more or less moisture resitant than DUPLEX.

the "hierarchy" of moisture resistance isn't clear on the web site.

 

[Richard C]

Duplex is a standard wallboard with a foil vapor control barrier, it’s neither fire retardant nor moisture resistant & neither is Fireline!

Which bit of the website are you looking at? Post a link.

 

[jono2000]

http://www.british-gypsum.com/products/plasterboard___accessories/gyproc_fire.aspx

does this mean that somewhere there is "standard" duplex??

still not sure of why there are so many different "moisture resistant" boards and what each one is for?

 

[Richard C]

does this mean that somewhere there is "standard" duplex??

Standard Duplex here;
http://www.british-gypsum.com/produ.../gyproc_standard/gyproc_wallboard_duplex.aspx

Standard MR board here;
http://www.british-gypsum.com/products/plasterboard___accessories/gyproc_moisture_resistant.aspx

still not sure of why there are so many different "moisture resistant" boards and what each one is for?

You don’t specifically need Fireline boards, they are to provide fire protection. Each range of boards is made for a specific purpose, fire retardant, sound insulation, thermal insulation, high impact etc. & there is a MR of Vapor control option is most cases. Your getting confused by looking in the wrong sections; you need ask your man specifically what he is proposing to use & where.

 

[jono2000]

update: the badly damaged wall is not plasterboard, but solid, plastered block and steelwork.

once the roof is fixed how long would it take to dry out the wall and plaster?

i can heat the room and put a dehumidifier in place to help things along.

once dried couldn't i just seal (thomsons damp seal?) the wall and repaint?

that would definitely reduce my costs.....

 

[1john]

a month per inch of thickness

 

[jono2000]

ouch!

the exterior wall would be 8-10 inches including plaster render.

so it would take 8-10 months to dry out

any way of speeding this up?