Basements waterproofing

At the time of writing, surveys need to meet the BS 8102:2009 Code of practice for protection of below ground structures against water from the ground, which gives provides guidance on dealing with and preventing the entry of water from surrounding ground into a structure below ground level.

As a house surveyor offering advice on waterproofing, or designing and supervising basement waterproofing, this is the standard against which your competence and performance as a surveyor can be judged – so the standard needs careful scrutiny.

It advises, for example, that 'a comprehensive survey should be undertaken of the existing waterproofing arrangements' to address the following:

1. Have there been previous attempts to mask dampness?
2. Which walls are earth-retaining?
3. Which walls are free-standing?
4. Are there cavities blocked by debris?
5. Is any drainage still functioning?
6. Are air bricks obstructed?
7. Are there signs of moisture penetration through the floor?
8. You should inspect adjoining structures – e.g. arches under steps.

This useful advice should be added to the other helpful pointers in the Surveyor's checklist: basements.

It is nearly always the case that you will be aware of a damp problem as soon as you enter a cellar or basement, just from the musty smell, and you will soon find damage caused by damp to building finishes – such as stains to wallpapers or paint finishes, rot to skirting boards, moulds underneath floor carpets, etc.

Finding damp in a basement is not usually the problem; the problem is deciding upon the best remedy to apply in the light of the available budget and site constraints.