Subfloor ventilation investigation

[Wellokthen]

First time buyers - got the results of our survey yesterday one of the things it suggested was investigation into sub-floor ventilation. some of the air vents are partially blocked by the drive and others are behind decking. It said there was no sign of rot but this could be discovered after “fitted covers are removed”.

im thinking this is something we should pay to get this checked out - but there’s no cellar- does that mean they’d have to rip up the flooring to check the timbers? Is it easy to put new air bricks in from outside?

They mean some idiot has blocked multiple airbricks and they need to be uncovered or new ones added. It can be done by digging, or you can get "periscope" vents which rise up a bit.

Idiots doing that are a common cause of damp and rot so you should get it fixed, and the subfloors examined to see how much damage has already been done.

If you ever have a new drive, have it dug out first to lower the ground level. A raised drive often bridges the damp course which causes more damp.

P.s.

If you haven't bought the house yet, see if there is another one that has not been foolishly maltreated. It will cost some thousands.

That’s a fairly standard surveyor caveat - they will add that in as they won’t have lifted any floorboards to check. How old is the property?

You need air bricks on opposite sides of the building to get air flow through the sub floor void. Lots of modern air bricks have small holes that are easily blocked as well. It’s not a big job to replace or add new air bricks - some types of cavity wall insulation can make it more difficult, so you need to know if that has been done.

What type of flooring is present?

You could give the surveyor a call as sometimes they will give you additional information.

If you go ahead with a survey then avoid using a timber treatment company as they will want to sell you stuff - go with an independent surveyor.

House was built in the 1980s. Not bought it yet this is just homebuyer survey, will it really cost thousands to put new air bricks in? Or do you mean if there is rot it will cost thousands ?

Floors are suspended timber, wooden flooring throughout.

I will call surveyor on Monday I think but do you know what type of survey we would get to examine this further?

if you have a builder in to dig out the buried airbricks, construct pits and open them up, and do the same under the decking, it will be a few thousand. If you have rotten joists and floor, it will be more.

it would be neater to dig a trench around the house, going down to at least the original ground level, and put large, clean cobbles in it so no-one falls in.