sub floor ventilation

[waynenavy]

What options are there for sub floor ventilation? does it cause damp wall if you dont have enough ventilation. If a damp proof membrane was not detected by my surveyer what type of damp proofing would it have, the house was completed at the turn of the century

[Savik2]

The damp proof course in a Victorian house is most likely to have been formed from slate bedded in mortar. This type of dpc is prone to deterioration with age. The quick solution is to install a chemical dpc, which is injected into the walls. Sub-floor ventilation is a different issue, but lack of it can be a cause of damp - though it will be from condensation rather than penetration. Sub-floor ventilation is usually provided via grilles or air-bricks set into the base of the outside walls of your house. If you had a Homebuyer's Survey done, then the surveyor should have commented on whether they are present or not. If not, you should install them. However, even if there are ventilation grilles, this is no guarantee that the sub-floor area is clear of obstructions that might prevent the free flow of air through the space. I'm afraid the only way to find out is to lift the floorboards and look!