You will often be told that dampness in the base of the walls is rising dampness caused by a defective dampproof course
or that there is no dampproof course
Don't insulate below the dampproof course
because the underfloor void will be vented like an attic.
And if there is a weak spot in the dampproof course
, the water will soak up into the upper wall.
Sub-floors such as concrete, asphalt, vinyl, quarry or similar tiled should be covered first with a plastic-film moisture barrier (a damp-proof membrane), in addition to any dampproof course
that may be present in the sub-floor.
However, the work done by the builder was later examined by an expert who found that the pointing unsatisfactory and insufficiently deep, while a dampproof course
was not needed.
Danny Graham, by email A Cut back any old mortar and get back to the sill brickwork, Lay a bed of mortar over the sill brick/ stonework, then lay a strip of dampproof course
along the mortar.
QI have just painted [...]; WHERE TO BUY: WWW.BHS.CO.UK, WWW.Debenhams.COM, WWW.Dobbies.COM, WWW.Dotcomgiftshop.COM, WWW.Homebase.CO.UK, WWW.ISME.COM, WWW.MARKSANDSPENCER.COM, WWW.PRESTIGEWICKER.CO.UK, WWW.Sainsbury's.CO.UK, www.tesco.com, www.wipeeasytablecloths.com In association with DIY EXPERT DONNY SHERIDAN ANSWERS YOUR PROBLEMS
The initial thought was that the cavity tray dampproof course
, set into the original side wall above the flat roof level, wasn't working and water was seeping down from the exposed upper wall and showing up on the internal lower wall.
AYou have a problem with your dampproof course
Plus, there were several small holes where the render didn't quite match after a dampproof course
was put in.