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What is Damp?

Damp Proofing Solutions from Wykamol

Over the next few days our news articles will be about the new damp proofing products we are stocking from Wykamol.  But first we need to explain what damp is.


What is damp?

Rising damp is a common problem in older properties either because no damp proof course (DPC) was provided at the time of building, or because a physical membrane has failed or been 'bridged'. In the majority of cases the provision of a remedial DPC is a cost effective and minimum disturbance option.

Dampness in buildings if left untreated can lead to structural deteriation; it will result in decay of timber, spoil decorations and can have problematic health effects through the development of moulds and mites.

When an absorbent material such as paper, wood, cloth or brick is placed in a damp atmosphere it will absorb moisture. If the humidity changes the moisture content of the material will change with it.

Wet wall, dry air

The air is unlikely to be at the above  RH if the damp is caused by water from another source such as rising or penetrating damp. If the wall is wet, it will be loosing moisture to the air through evaporation all the time. However, constant water rising through the masonry will cause damp patches, salt marks along with associated mould and fungal growth. Typically this is caused by the absence, failure or bridging of the damp proofing course.

Salt conta­mina­tion due to rising damp.

The source of rising damp is the soil or sub-soils which are always wet. Soils consist of biodegraded plant matter hence water in soils is nor pure and usually contains nitrate and chloride salts. These rise through the masonry and are left behind as water evaporates. Rising damp over a number of years can cause high levels of salts in masonry. These residual salts are hygroscopic; hence they contribute to the problems found.

Rising damp results from the capillary action of water from the ground. In the absence of an adequate DPC a zone rising to around 50cm (or more) above the skirting level along the whole length of the wall will result. Where the DPC is damaged or breached, patches of dampness may occur.

So now we know what damp is and where it comes from tomorrow we will tell you how to remove it.


Greengates Builders Merchants delivering to the whole of Lancashire including: Accrington, Blackburn, Burnley, Clitheroe, Darwen, Great Harwood, Haslingden, Padiham and Pendle.














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