cavity trays

Sponsored Links
You should have a DPC or DPC's at 150mm above ground level.

Are you proposing fixing some kind of frame into a basement?

What, exactly are you attempting?
 
Hi its an extension we are at dpc level but i was wondering if you need a cavity tray with weep holes above dpc level?
 
Hi its an extension we are at dpc level but i was wondering if you need a cavity tray with weep holes above dpc level?

You need some way for water tracking down the inside of the outer leaf to get out. This is commonly done by ensuring the cavity in open down to 225mm below the DPC, i.e. 75mm below ground level.

If very high levels of water penetration is likely, or there is radon gas issues, it may be preferred to have a cavity tray at DPC and weep holes. Best to ask the BCO which is required in your area, or there are tables in the building regs.
 
Sponsored Links
If it's a normal blockwork wall, you don't need a cavity tray at ground level - just a normal dpc for each leaf.

An exception is if you have to have a radon barrier, in which case this has to be continuous across the cavity, requiring a cavity tray.

Have you had plans drawn for this? What do they specify?
 
no there isnt any plans its only a small extension, I was just wondering because i didnt want to start the brickwork and then the building inspector say after it should have one, im just being over cautious
 
If you are doing it from a Building notice and are unsure of anything, it's best to check first with the BCO.
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Back
Top