Which undercoat plaster

[paul_v]

Hi everyone, i will soon be re doing my kitchen and will have some plastering to do. The walls are all built using aircrete concrete blocks, there is to be a new doorway in one wall so i will be putting in a concrete lintel. Ive looked at british gypsum's guide and it says you use hardwall for the aircrete blocks and bonding coat for precast concrete ie the lintels.

So my question is which one should i use as i surely cant use both. Ive done some plastering before to a good standard so being able isnt the problem

here's bg's guide i used: http://www.british-gypsum.com/pdf/LIT_Thistle_Plaster_selector_guide_A3_poster_03.pdf

I have a second question, were hhaving glass upstands instead of tiles, im going to remove the old tiles and skim the wall to recieve the glass upstand and paint the rest of the wall where the tiles used to be. Can i just remove the tiles, coat with bondit or blue grit and then skim with multi finish?

Thanks Paul

 

[trowelmonkey1]

you either need to get a key on the lintel and use hardwall or kill the suction on the wall with plenty of PVA and use bonding coat.

 

[peaps2]

Using bonding or hardwall in a high moisture area can promote damp.

 

[trowelmonkey1]

is that our helpful advice to he customer again?

The lightweight nature of gypsum will give slightly warmer walls than cement or lime render and its ability to absorb a small amount of moisture and release it again means it's fine in a kitchen unless you start throwing water at the walls.

NEVER seen a problem of mould/damp in a kitchen that has been caused by gypsum being on the walls.

 

[peaps2]

damp isn't the only problem you may face, adhesion is also a problem.

bonding doesn't do moisture, ask BG