Hi I am looking for an alternative decking joist for a deck I will be
constructing soon . It will be on three levels the lowest of which is
partially resting on concrete and needs to be approximately 88mm high
(50mm thick joist plus the deck) as this does not give much of an air
gap my ideal solution would be some kind of plastic joist which I can
screw directly onto the concrete.
Does anyone have any ideas as to what I could use or other cheap
alternatives that I can screw decking onto easily?

Housemartin wrote:
Hi I am looking for an alternative decking joist for a deck I will be
constructing soon . It will be on three levels the lowest of which is
partially resting on concrete and needs to be approximately 88mm high
(50mm thick joist plus the deck) as this does not give much of an air
gap my ideal solution would be some kind of plastic joist which I can
screw directly onto the concrete.
Does anyone have any ideas as to what I could use or other cheap
alternatives that I can screw decking onto easily?

In a situation where the joist rests on concrete I lay the joist on lengths
of DPC.

As long as you have a suitable gap between boards it will have enough
ventilation.

Assuming a 28mm deck board + a 47mm x 47mm joist you still have 13mm under
the joist anyway.


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257

In a situation where the joist rests on concrete *I lay the joist on lengths
of DPC.

As long as you have a suitable gap between boards it will have enough
ventilation.

Assuming a 28mm deck board + a 47mm x 47mm joist you still have 13mm *under
the joist anyway.

--
Dave - The Medway Handymanwww.medwayhandyman.co.uk
01634 717930
07850 597257

So you would raise the joist up off the concrete slightly,and would
that be a bitumen based type DPC or just the thin plastic type?

Housemartin wrote:
In a situation where the joist rests on concrete I lay the joist on
lengths of DPC.

As long as you have a suitable gap between boards it will have enough
ventilation.

Assuming a 28mm deck board + a 47mm x 47mm joist you still have 13mm
under the joist anyway.

--
Dave - The Medway Handymanwww.medwayhandyman.co.uk
01634 717930
07850 597257

So you would raise the joist up off the concrete slightly,and would
that be a bitumen based type DPC or just the thin plastic type?

Always best to keep them off the floor if you can. I tend to build the
frame first & then level it using the noggins - placed on plastic DPC. The
noggins don't have to be flush with the top of the joists.


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257