How to increase air flow under our house?

[selvins]

Hi

We are wanting to increase the air flow under our house

 We already have a ventilation fan under the house, but would like to widen our outside air vents to help further cross ventilation.

Is it OK to cut the cement/brick and widen the existing vents, or could this cause damage to the structure of our house. If so, how would we do this?

Thanks!

[EricL]

Hello @selvins 

Thanks for sharing your question about increasing air flow under your house.

In this particular situation, I suggest engaging the services of a registered builder who has experience with brick foundations. I propose adding more ventilation points along the wall rather than making a very big hole. For example, you can add a Builders Edge 230 x 165mm Galvanised Brick Vent With Mesh.

The Builders Edges Galvanised Vent helps prevent rising damp and the rotting of floor joists. By adding more ventilation entry points you'll get a better spread in regards to air circulation under your house.

Let me call on our experienced members @Nailbag and @Dave-1 for their recommendations.

If you have any other question we can help with, please let us know.

Eric

[Dave-1]

Afternoon @selvins 

Definently I would be taking @EricL 's suggestion about engaging a builder to do that particular job. The more ventalition points I like over a larger hole as well.

Just because there has been a few questions about water / damp under the houses after the rain we have had over the past few montsh I am wondering if you have water under you house? If so then id probarly investiage where it is coming from plus the more ventilation option. Even newer houses dont necasarily have lots of ventilation through the brickwork. (thinking back a few years at differnt places I have lived in)

Please Note ***

For a large hole a lintel would be needed. Doing this yourself without knowledge could end up causing cracking later on to the surrounding brickwork, as the stresses released relax.

Dave

[selvins]

Thanks Eric. I'll follow your advice and look at getting more vents, fitted by a builder.

[selvins]

Thanks for your advice Dave. I believe under our house is very dry, at least that is what our plumber has said. However, one side of the house lacks cross ventilation, and that is the side where we have mold inside the house (on furniture). I think from what you and Eric have explained, hiring a builder and adding more vents is the best option. 

[Nailbag]

Hi @selvins I can't add any more than the great advice @EricL has already suggested. If you're going with a builder, make sure they are registered as only they have qualifications on load bearing structures. A qualified bricklayer would also have the skillset and probably the one that would actually do the work. 

Basically a square hole for each air grate will be marked out and a horizontal slot will be cut out along the top and extend to each side. A steel bar (lintel) will be inserted to support the opening. Then the grate can be fitted and mortared in to place. A simple, though time consuming job.

Regards, Nailbag

[selvins]

Some great advice there Nailbag! Thanks so much