How to ventilate floor void.

[competentnovice]

Hi all.

I've got a bit of a rot problem due to damp sub floor. I think I know where the source of water is coming from. (Leaking garage adjoining house flowing into air brick.) and I'm in the process of making this watertight.

Upon lifting some boards there is quite a lot of debris in the void due to lazy builders which I will get rid of.

However, the area affected is quite damp underneath and I think this is due to lack of airflow.

At the front of the house I have a concrete porch, thus blocking air bricks at the front.
At the rear I have a concrete floored kitchen again, no air bricks. And directly to the side, I have a garage with a concrete floor - no airflow.

The walls are cavity. Any ideas how I can the air moving underneath? I was thinking of some sort of fan, but wouldn't know where to start.

Any ideas??

Cheers

Matt.

 

[vinn]

Your post is confusing.
Exactly how is water getting into your sub-area?
What do you mean by: "making it watertight"?
Have you crawled under the floor yet?

Photos of the areas in question would help esp. the rotten and damp areas.
A scan of a plan view showing any "working" air bricks would also help.