How do I support decking boards on an Alfresco with very low clearance (75mm)?

[SamHa]

Hello!

I'd like to lay composite decking over the top of our undercover alfresco however there is very little clearance (75mm from concrete to the top of the door tracks) for joists and other substructures like tuff blocks. The alfresco is 3,740mm x 3,910mm, has a slight slope way from the house and about a 200mm drop off to the ground.

Most of the resources I've seen cover decks which are either not under cover or have a bit more clearance. Is it feasible to put down decking boards on an alfresco like this or would I be better off considering tiles?

Thank you!

Sam

[JacobZ]

Hi @SamHa,

A warm welcome to the Bunnings Workshop community, it is fantastic to have you with us.

Unfortunately, 75mm is not enough height for a timber deck. The lack of airflow beneath the deck will cause trapped water to sit there, unable to dry up, which will cause the deck to rot far faster than is reasonable for the expense.

You are much better off looking to tile the area, as tiles can exist in a moist environment without any issues. You might like to have a look at our selection of outdoor tiles for some inspiration.

You might like to check out How to tile an outdoor area for some guidance.

Jacob

[SamHa]

Hi @JacobZ thanks for the reply!

I was hoping with a metal subframe there would be enough clearance/airfow but on second glance the 40mm clearance is only with sufficient drainage

I don’t suppose being fully undercover and using a wider board spacing mitigates this?

Thanks again!

Sam

[EricL]

Hello @SamHa 

I'm sorry but those factors you mentioned will not be enough to mitigate the accelerated deterioration of your deck. I can only suggest what Jacob has mentioned and that is to tile the surface in order to give it a different look.

If you need further assistance, please let us know.

Eric

[SamHa]

Thanks for all the help @EricL and @JacobZ!

I’ll take a look into tiling as an alternative, originally we were going for decking so we could extend it later but we’ll look for tiles that won’t clash.

Thanks again!

Sam