Wet walls in residential property.

[de_ja]

The property was constructed in approximately 1920s. located in East London. I have symptons such as the front lounge room wall in one corner at the front of the property which is wet to tocuh when it rains, from the floor to about one meter height. This also occurs upstairs in a front bedroom, the wetness on the front wall starts from the floor to about one meter and half height which occurs when it rains.

It seems abit odd that on both the ground and first floor the dampness affects the area from the floor level to half way up the wall.

Looking from the outside there are no obvious signs of rain water getting into the walls, the darin pipes do keep the water away.

Has anyone any idea what my problem might be and what I should do about it.

Thanks

[Phil L]

Is it in the same corner of each room? - that is to say, if it was an overflowing down pipe, would this fit in with where the dampness is? - itm could be coming down the cavity if you have finlock gutters, these were popular round about 1900 - 1930 in various parts of the UK, although some places don't seem to have any at all, see some pictures here:

of those in the above link refer to concrete ones, but sandstone ones were used back then and the principles are virtually the same, the stone channels are laid on top of the wall for the roof to drain into, and the channels were often lined with lead sheet, but sometimes not, and water gets through the gaps where the stone channels meet, or even if they are lined with lead, it sometimes deteriorates or gets stolen(!) and the water goes through the gaps, down the cavity and can cause damp, especially where it meets an obstacle, like first floor joists (your upstairs damp) and downstairs joists or the bottom of the cavity (your downstairs damp).

Of course, all of the above would only apply to you if you have stone or concrete gutters, if you haven't, then whatever your gutter is made of has deteriorated at the back edge (the bit you can't see from the front) and water is pouring down the walls when it rains- - very little will reach the down pipe. Either this or the roof materials don't reach the gutter - possibly a broken tile or slate has slipped down creating a void immediately before the gutter.

HTH

[Cash]

de_ja,

Just a few quick questions to clarify things:

1 Are the external walls stone or brick? 2 If they are brick, are they cavity - or solid walls [1] (9" or 13" thick usually if they are solid)? 3 What is the internal wall finish - black mortar or gypsum plaster? 4 Are there any water pipes (waste or mains) running through the wall near to, or directly above the damp patches. 5 Are these damp patches below any windows or near any wall vents

Ground Floor Damp:

Your description could indicate rising damp - usually caused by damaged DPC (or lack of one) [2].

First Floor Damp:

This could be caused by water penetration through a defective external window cill.

Other reasons could be water penetrating through (now) porous solid brick/stone walls -- or across blockages in any cavity, dirty wall ties [3] - or even water dropping down any cavity from a defective roof [4].

Could you also let the group know if there are any other 'unusual' features in the construction of the property that may cause the problems

[1] If you don't know how to check for this, see the following Tinyurl link and scroll down to the two wall diagrams at the bottom of the page. Not guaranteed as it could be caused by other problems - such as internal leaks running along the floor (look for wet or damp carpets etc). [3] If that were the case, then it's probable that the walls would be stained internally by small, brown patches (especially if it is a wall tie problem or a brick or bit of rubble jammed across any cavity). [4] Damaged eaves tiles, or underfelt (if fitted) or even a missing roof tile which allows water to run down on top of and felt and dropping into the cavity if the end of any felt has rotted.

These are some of the common causes and I hope this information may be of some help.

Cash