Dealing with dampness in foundations

One of the annoying things for most homeowners is to see painting and plastering peeling off around the house especially a few centimetres above the ground. Fortunately, this problem can be avoided if construction is done the right way. If the problem has already occurred, there are some remedial actions that can be taken. In this article, we explore how to avoid the problem from taking place.

Plastering

When plastering, ensure that there of a strong mix of cement and sand. Recommended mix for most cement brands found is Zimbabwe is 1:3 or 1:4 with the former being stronger than the latter. However, these ratios confuse many builders as they think that a ratio of 1: 4 means 1 bag of cement as to 4 wheelbarrows of sand. This is not the case, instead, it means 1 volume measure of cement to 4 volume measures of sand. Therefore, a wheelbarrow carries approximately 2 bags of cement and as such it means that 1:4 ratio has 2 bags of cement and 4 wheelbarrows of sand. This information is readily available on most manufacturers’ cement packaging bags.

Waterproofing

In addition to a strong mix, mortar for plastering such wall sections ought to be mixed with some waterproofing powder and in Zimbabwe the popular one is called impermo which comes is 1kg bags at a cost not exceeding US$2 a bag and the equivalent number of cement bags required is the amount of 1 kg bags required. Alternatively, one can use waterproofing cement.

V-Joints

After plastering, the demarcation between the foundation and the superstructure where the damp proof course (DPC) is, should be V-jointed. The V-joint is a recessed line, that is created by pressing down a handheld tool with a v-shaped or round shaped end along the fresh plaster, thus created a recessed line. The idea is to ensure that if by any chance moisture goes up the wall, it should not go beyond the V-joint. Moreover, if there is damage to the section below DPC level, the repairs are manageable.

Waterproofing paint

It is recommended that the paint that is used below DPC level be a waterproofing type of paint such as Dulux’s dampshield and this is normally different from that which is used for the rest of the walls.

Conclusion

Building is a lifetime achievement for most people and there are certain not so expensive practices that ought to be followed to avoid future problems. To avoid moisture damaging the external part of your house, ensure proper mixing ratio of cement to sand, use impermo, v joints, and waterproofing paint.