The forecast is that summer is to end early and the Costa del Sol is to see rain and lightning storms on Monday to Wednesday this week (28th to 30th August). Normally, it has the decency to wait until all are back at school and the office, but this year it’s different.
Damp is the most common fault we see in our building surveys and much of it can be avoided with a little preparation.
Start at the top. Are all the terrace drains clear of weeds and debris and water able to flow down them and away easily? Remember that when it rains here, it can really come down in large amounts so every millimetre of pipe width is important. Otherwise the rainwater ponds and finds its way under the tiles and through into the areas below, or around the patio doors and into the house that way. It’s too late to install new gutters and downpipes, but make sure if you have them that they too are clear and the end of the downpipe directs water away from the building, ideally into a drainage system. Where is the water going from the terrace? We see spouts pouring onto terraces below, with a fierceness to wash away the grout from around the tiles there. Once water gets under tiling, it can flow to the walls and cause damp internally for many years. So, ensure that any water falling from above is caught, even in an empty flowerpot and allowed to overflow from there, which will avoid the damage to the surrounds of the tiles.
Down at ground level, again make sure that all the drains are vegetation and debris free and that the run-off water will pour through them and off your parcel of land. Make sure that if this water drains onto a downward slope that it doesn’t create a gully and encourage erosion, which could cause collapse of the areas above in the future. Make sure that the ‘weep holes’ in the retaining walls are clear so that water is not held behind the wall, greatly increasing the weight it has to retain and perhaps even causing collapse. Behind the walls, and around the foundations of the house, there should be a field drain system installed below foundation level. The area immediately behind the wall should be protected by loose aggregate infill before the earth is heaped against it, again permitting the water to drain down to the field drain rather than being held against the foundations and lower walls of the house, which will eventually cause it to be drawn up and through as rising damp.
The slopes in gardens and the hillsides above also should have their drains cleared to direct the water running down them away from the house.
It’s all a matter of avoidance and ensuring that rainwater is guided away from the building and allowed to carry on downhill as gravity dictates.