Concrete floors and cavity

[Nick2847]

Thanks @Mr Chibs for all your advice.

I have researched alot about damp and ventilation but building construction is beyond me so all of the responses have been very helpful.

 

[Nick2847]

Update.

Just to quickly revive this thread, I've had a brickie come and inspect the air bricks with an endoscope and they are only 2 brick widths deep. It is then the DPM and hitting the concrete subfloor. Inside is a solid concrete floor and a second DPM stood up around the skirting boards.

So to confirm, is blocking up the airbricks a good solution to prevent any damp ingress?

The slate DPC is just above the airbricks. Will replacing the airbricks cause any damage to this?

Could these airbricks be ventilating a cavity wall? Or will sealing them possible cause internal damp/ a rise in condensation levels inside?

The reason for blocking the airbricks is that the ground level is just below the airbrick height and the brickie said that below this is the foundations so can't dig any lower. My house is on a slope from the main road to my front door, driveway rightly slops away from house, but this area was also flooded in 2020 so blocking the bricks is to prevent any water entering the underfloor space with the now lower ground levels around the house.

Thanks all, want to make sure I am doing the right thing to my family home.

 

[sxturbo]

Are they cavity walls in such an old house?

 

[Nick2847]

Are they cavity walls in such an old house?

I don't think so but have been told on here before that eleven inch walls can be cavity walls, even in my old (1907ish) house. I'll be asking my brickie to do a bit of investigation next week.

 

[Mr Chibs]

Morning

looking at your original images, you have solid brickwork. Usually this is 9” wide.
If you have thicker, it could be older bricks are wider than modern sizing and/or you have a cavity.

My house is similar age and is solid brick, from memory is just over 10” wide.

My guess is no cavity. If you remove the air vent grille, you will be able to get your hand in and feel if there is a cavity.

As you have solid floor, the air vents are no longer used and could be bricked up.

The slate dpc will be unaffected.

Internal damp could be breeched/damaged/no dpc and/or poor ventilation inside... open windows each day to lower humidity levels.

 

[Nick2847]

Thanks again @Mr Chibs

My plan is to brick up the air vents, drop the ground height to prevent breaching the slate DPC and ventilate as much as possible.

Thanks all for the advice, you have put my mind at ease.

 

[Tigercubrider]

You can buy an endoscope that sends to a phone.
£25 from tool station
I had a “proper “ one which died so bought one and it’s ok