Ventilation Question

[marsman802]

Hi All

I've had a visit from a damp proofing specialist who has given me some advice on my two front bedrooms where I have mould growth issues on the outer walls.

I have double glazed windows that have no trickle vents.

He has recommended the installation of black hole vents into both front bedrooms (I should probably do the back bedroom but it's unoccupied at present and can wait) but has said to install two vents per room; one at the top of the room and the other at the bottom (but not directly in line with each other).

I've had a hunt online and I haven't found similar resolutions at this stage.

Are two vents per room normal?
He has also quoted me £624 inc VAT for the entire job.

 

[tony1851]

If one is at the bottom, the room will be draughty

The price is a rip-off, too.

 

[marsman802]

If one is at the bottom, the room will be draughty

The price is a rip-off, too.

But why suggest a second in the room itself? He mentioned something about air circulation but surely one vent is going to allow both air in and out?

These black hole vents reduce most of that draught from I've read but I'd be keen to hear from anyone who has experience those?

This is only the first quote - I want to be sure of the requirements before putting it out to other tradesman.

 

[Gazman16]

It would be easier and cheaper to open the windows occasionally.

 

[marsman802]

It would be easier and cheaper to open the windows occasionally.

It would be cheaper but just not practical for our situation. I'm happy to spend the cash but I don't want to over engineer the solution.

I would've thought 1 vent per room would be a good start point and install a second if that doesn't do the job?

 

[Gazman16]

You can retro fit trickle vents into windows, They are about £5 each from ebay. If they are open and internal doors are left open that should allow air circulation.

They can be a bit of a pain to fit though, Especially if your windows have steel reinforcement.

Do your windows not have a night vent option where you can lock them slightly open?

Personally I hate trickle vents. They are noisy, Drafty and let insects in.
If your happy to spend some money my plan of attack would be to upgrade to good quality humidity sensing vents in kitchens and bathrooms, And maybe a dehumidifier.
Also try to reduce moisture in the house. Dont dry clothes inside, Open a window while cooking and showering etc, Leave internal doors open when possible to allow air circulation.