plaster or plasterboard when resolving dpc issue? Ask your questions and find answers on many subjects relating to plastering and dry lining

[SaraC]

I am trying to work out whether to use a salt retardent plaster or a thermal plasterboard when replacing the plaster of my ground floor living room walls, to resolve a dpc issue. The room is long and narrow so I am concerned about losing space with the plasterboard solution, but the reading Ive done and advice Ive found suggests that it will be more heat efficient and quicker/easier to install than a new plaster. Has anyone had any experience of these materials that could offer some advice on suitability or potential loss of floor space?

[u]Some background[/u]
I have an old house which had a damp proof course put in by the previous owners (1999). They then sold the property to me (2001) and I have finally got around to removing the wallpaper in the living room only to find signs of damp which upon investigation showed that they didnt replace the original plaster as instructed. This has made the guarantee Ive inherited invalid. The DPC company who provided the original guarantee are writing me a letter to confirm that if I do the work now as per their specificiation the guarantee will be valid as following their inspection they are happy the DPC is still ok. They are specifying the suitable materials for both options (salt retardent plaster or thermal plasterboard) and I believe there is a drying time for the plaster before adding a skim/paint etc which must be adhered to if the guarantee is not to become invalid again (this would be another argument for the plasterboard). I just need to decide which is best taking everything into consideration: depth/cost/effectiveness - oh and speed to completion!

[ALDA]

SARA,

MOISTURE RESISTANCE IS AN IMPORTANT CONSIDERATION.

WALLS SHOULD BE SOUND AND WEATHERPROOF BEFORE APPLYING A THERMAL PLASTERBOARD LAMINATE.

DAMP WALLS COULD HAVE A DETRIMENTAL EFFECT ON ADHESIVE PERFORMANCE IF CHOOSING DOT AND DAB METHOD OF INSTALLATION.

WHEN LINING INTERNAL WALLS IN REFURBISHMENT PROJECTS THE EXISTING WALL IS OFTEN IN A STATE OF DISREPAIR, WHICH CAN MEAN DAMPNESS.

THE POLYFOAM INSULATION BACKING TO THE PLASTERBOARD IS RESISTANT TO MOISTURE ABSORPTION AND CAN OFFER THE BEST PIECE OF MIND SOLUTION FOR AN APPLICATION WHERE POTENTIAL MOISTURE INGRESS IS A CONCERN.

IF IN ANY DOUBT ABOUT ADHESIVE USE MECHANICAL FIXING METHOD.

ALDA.

[SaraC]

Good points. thankyou. All this learning is so much fun, I just wish Id planned in time for it :D

Do you know how much floorspace I am likely to lose or if there are ways of minimising it? Ive found backed thermal plasterboard at about 50mm but Im guessing you need a gap and people have mentioned to me I might lose up to 2" all round which would be a lot of space in a narrow room.
I figure that you have to assume that you are knocking a good half an inch of old plaster off the walls but if the replacement is much more than that you start to lose floor space..

This would be dissapointing as I took the wallpaper off the walls with the intention of painting it to create the impression of a bigger room!

thanks again

[ALDA]

PLASTERING = 0.5-1" ON ALL WALLS.

BOARDING (DOT AND DAB)= 2-3" ON ALL WALLS.

BOARDING (BATTENING) = 3-3.5" ON ALL WALLS.

BETTER THERMAL INSULATION WITH BOARDS.

AT THE END OF THE DAY IT IS YOUR CHOICE BUT IF SPACE IS AT A PREMIUM AND OF GREATER VALUE TO YOU THAN WARMTH THEN GO WITH THE PLASTERING OPTION.

DECISIONS DECISIONS,

ALDA.

[Briggy]

Hi, if i were you i would get an independant report done, sounds like your being fobbed off a bit to me. If the dpc,dpm were replaced properly, or walls injected properly nine years ago you shouldn't still be having problems! Also if your taking the plaster back to the brick, tank it out, dot and dab moisture resistant board or fix the same to battens,and plaster or tape and joint, either way you won't come off the brickwork more then an inch to an inch and a half (no offence to the last comment but some figures a bit excessive) or alternatively a render coat with an integral waterproofer, then skim! Hope this helps, Regards!

[ALDA]

BRIGGY,

SUGGEST YOU RE-READ SARA'S 2nd POST IN ORDER THAT YOU MAY ADJUST YOUR ADVICE GIVEN IN YOUR POST!!!!

ALDA.

[chris_on_tour2002]

[quote]I have finally got around to removing the wallpaper in the living room only to find signs of damp which upon investigation showed that they didnt replace the original plaster as instructed. This has made the guarantee Ive inherited invalid. [/quote]

i agree with briggy that you are being fobbed off a little. if the dpc was done in 1999 you should not be having problems now. bear in mind that these companies will look for the slightest reason to exonerate themselves and absolve themselves of any responsibility, especially if its a financial one. after all it could mean lots of expensive repair work that they have to stump up the readies for.

if the plaster is still damp it does not matter if it was replaced at the time or not after this time it should have dried out. if damp is still coming through then its the damp protection that is at fault. take issue with them, and get an independent survey.

[Briggy]

Hello again, just to add to last post, Sara seemed more concerned with loss of space then thermal properties! i was trying to find a happy medium for her problem! so thermo board would be good , you also can get a basic thermo board as thin as 22mm, i was just trying to give advice , with space saving in mind, Like i said before though , and Chris agrees, you need to solve the problem first!

[ALDA]

HI BRIGGY,

I AGREE ENTIRELY ABOUT RESOLVING THE ROOT PROBLEM.

AS SARA NEVER CAME BACK TO GIVE US AN UPDATE ON HER PROJECT IT IS HARD TO SAY WHICH WAY SHE WOULD GO ON THE MATTER.

AS YOU WILL FIND ON THIS FORUM, PROGRESS REPORTS ARE FEW AND FAR BETWEEN AND ALSO POSTING TIMES ARE POOR.

IF THESE TWO GRIPES WERE IMPROVED UPON, THEN THE FORUM WOULD BE EVEN BETTER THAN THE 7 OUT OF 10 THAT I CURRENTLY RATE IT AT.

HOW ARE YOU FINDING IT ( AND ANYONE ELSE THAT CARES TO COMMENT) ?

CHEERS,

ALDA.