Need some advice

[cornishcarpenter]

Hey guys,

Got a house renevation coming up, the customer has asked me which is best to deal with her downstairs wall which is the exterior wall of the room, its damp, the old plaster is peeling off. i have given her 2 options was thinking what you guys would do?:

1. Rip all of the old plaster, seal and plaster with a lime mix or

2. Line with plastic clear sheeting (dont no tech name for it) build stud wall with 2x1 and use plasterboard with instulation built on the back.

which you guys think is the best, i am thinking the second as it more insulation and keeps the damp away.

Do i need building regs on this sounds stupid but just checking?

 

[ajrobb]

Where is the damp coming from?

• condensation
  hygroscopic salts
  penetrating rain (pointing)
  bridged DPC

I assume the wall is solid. I can't see the point of combining permeable lime plaster with a brick sealant. If the problem is condensation, sealing the bricks could stop the plaster drying. If the damp is external, sealing the inner surface might cause spalling.

Clear plastic is probably vapour proof and should not be placed on the cold side of insulation. A VPL on the warm side of the insulation is often included in insulated board. Kingspan K18 is recommended for solid walls with treated battens (at least 25mm, preferably 50mm) on the bricks. Celotex GA3000 can be placed against the bricks, held in place with battens under the plasterboard.

 

[Deluks]

Has this customer just bought a property that has been empty for a while?

 

[Static]

Fix the cause of the damp first then do the repairs..

Another one to add to ajrobbs list would be ground level externally higher than internally..

 

[ajrobb]

As Static says, fix the cause.

Speaking with the nice people from Heritage House about insulating solid walls, they like to erect a galvanised steel frame spaced off from the wall to allow air circulation to dry the bricks/masonry. They hate chemical treatments.

If the problem is condensation caused by lack of ventilation, consider positive ventilation products, like Nuaire Drimaster, other topic threads have sung their praises.

 

[gregers]

or is it rising damp,or doesnt that exist anymore

 

[cornishcarpenter]

Hey guys

The wall is solid cornish stone, its not really damp, just slightly, the house is empty been like that for a roughly 2 months i think. The custome wants the house in a state where she can live it over the summer then start major work in winter. The outside of the wall may need repointing so thsat can be done whenever. How far does the battern need to sit off the wall, so air can circulate?