concrete plinth

[dave7]

Hi

Around the bottom of my house is a concrete plinth like render all the way round, and its all crumbling off, so had a deeper investigation of it too me it does not serve a purpose its comes up three courses of brick and covers the damp proof course.

Can i just chip it all away and be done with it or would i need to re instate it once i have removed it all?

Have had a nose at my neighbours house and theres seams fine, the house is about 40 years old and is part of a large estate.

Thanks

dave

 

[Joe Malone]

Dave, the purpose of the plinth is to protect the wall base against lateral penetrating damp and rainsplash. However it shouldn't be bridging the dpc. Clearly someones gone for a belt and braces approach here but providing you've definitely got a physical dpc in place then you're fine to remove it.

 

[dave7]

thanks for the quick reply,

by physical dpc, you mean what looks like thin roofing felt runing in the 3rd course from floor level all the way round, and it is lower than the internal floor level?

What puzzels me is that all the houses in the street have this bit of concrete running all the way round the bottom, i thought it was bad practice to cover the dpc with anything.

In some areas the plint has been repaired because it came away at the top and stayed fixed at the bottom, it must have been fixed to prevent rain getting behind it.

dave

 

[Joe Malone]

Yes, sounds like you have a bitumin felt dpc. Should be lower than the internal finished floor to protect the floor timbers from damp. It is bad practice to bridge the dpc but because these plinths were additional protection against damp it was often wrongly assumed that it would be ok to render them over the dpc. Initially it wouldn't cause a problem because portland cement is impermeable to damp; however after 30 to 40 years it degrades and becomes porous. This is when it will start to wick moisture up past the dpc by the process of diffusion.
It certainly wouldn't do any harm to replace the cement plinth but if you do then it needs to stop an inch short of the dpc. [/img]

 

[dave7]

great, thanks think il just take it all off and leave it looks alot nicer without it.

cheers