Should flashing and cavity trays be provided to canopy roofs?
The simple answer is yes!
But with so many different examples of canopy roofs, each with different requirements on providing weather protection, it can be difficult to work out when flashings and cavity trays need to be used.
We’ve divided them into three main categories to help you identify what you need to provide and when. We’ve even put them into an easy to understandable table which you can download here.
Here are the main categories we’ve identified:
- Site Formed Canopy eg front entrance door canopy
- Prefabricated (GRP) Canopy
- Site Formed & Prefabricated Canopies over Habitable Accommodation eg Walk in bay or enclosed porches and conservatories
- Site Formed Canopies
This is where a canopy is made on site over a non-enclosed door in order to provide weather protection for the construction materials such as the brickwork. With site formed canopies a suitable lead or lead alternative flashing is required between the canopy roof and the external wall.
There is no specific requirement for the flashing to be linked to a cavity tray for site formed canopies. However it is still expected that a cavity tray should be installed over the external door opening.
- Prefabricated (GRP) Canopies
Although some manufacturers of prefabricated canopies may suggest that only silicone sealant is needed to provide weather protection this is not the case if you want to be covered by your warranty. Unless the canopy has a third party product approval stating that this is sufficient you will be required to provide a suitable lead or lead alternative flashing as with the site formed canopies. The same also applies for the cavity trays.
- Site Formed & Prefabricated Canopies over Habitable Accommodation
When using both types of canopies over habitable accommodation, for example an enclosed porch or conservatory, the rules change. The flashing in this case must be linked to a cavity tray at all times.
So if you want to be covered for any structural defects make sure you use flashing when installing canopies to houses and where necessary link this to a cavity tray.
For a detailed summary, why not download our easy to follow table.