Deck joist and beam protection

xl500

Has anyone ever put waterproof tape on top of deck beams and Joists before laying deck boards seems like it could help extend life of frame

Thx
Xl500

jack of all

No and never seen it down either, problem bei g that if water does find its way underneath a membrane it's trapped and will contribute to decay Think about the old tradtional flat roof with a felt covering- when the felt was reaching the end of it's useful life water would find its way under in places and this is where the deckwould be worst affected by rot. Best practice is to design timber constuctions so that water can drain away or air can ciculate ti promote good ventilation and speedier dryi g out .

Lumen

xl500 wrote: »

Has anyone ever put waterproof tape on top of deck beams and Joists before laying deck boards seems like it could help extend life of frame

Thx
Xl500

I put breathable membrane around my cantilevered deck joists.

It's probably not worth doing on a regular deck because the frame will outlast the boards, but I did it because the joists are irreplaceable.

Membrane is Pro Clima Solitex Fronta Quattro
Tape is Pro Clima Tescon Invis

edit: I did put in some 3x3 noggins to give me something to screw into. They were similarly wrapped.

wait4me

Lumen wrote: »

I put breathable membrane around my cantilevered deck joists.

Nice job overall!

livingthedream

I put a deck in my back garden circa 10 years ago and really lashed on the creosote at the time. The softwood boards on top were treated each year as you should and lasted up until a few months ago.

When I lifted the original boards, the joists were still good enough to lay new boards over them. There was one spot where the weren't as good and I think that is because there was a large item directly over them for many years so not as much air movement around them possibly?

As with 'jack of all' I would be concerned with any membrane that if moisture got under it that it would be trapped etc... but hey I'm no expert, a mere DIY'er My advice would be to be generous with the creosote!

~LTD.

Lumen

livingthedream wrote: »

As with 'jack of all' I would be concerned with any membrane that if moisture got under it that it would be trapped etc

The point of a membrane is that it lets water vapour through but blocks liquid water. That's what's meant by breathable. Totally different to a vapour or water barrier like polythene or DPM, which you might put under the joists to stop water soaking up from supporting blocks.

I used the membrane partly because I had a load of it lying around.

Anyway, Robin Clevett did some videos on using tape, like this

https://www.youtube.com/watch?v=6l_uj20v7c0

Now I'm a bit suspicious about affiliate sales from Youtubers, but I've watched loads of his videos and his work is first class.

RainInSummer

xl500 wrote: »

Has anyone ever put waterproof tape on top of deck beams and Joists before laying deck boards seems like it could help extend life of frame

Thx
Xl500

It's more of an American thing. I built a composite deck with timber framing and I covered the tops with butyl rubber tape.
Basically I did what the installers in the States do. I don't know better than them so I copy what the pros do.