Had to replace a few planks of decking due to rot. Bought the replacement decking and fitted a piece but it looks like its about 3mm thinner (in depth) than the original decking resulting in a bit of a hazard. Need to put something to build up the new strips so that it’s all the same height. What would be good to use?

Plastic frame spacers from screwfix or similar should do the job. Come in a large mixed thickness bag so you can build up whatever height you need.

Bits of 3mm or 1/8″ plasticky anything really 😉

Bits of fascia board.

Sounds to me like the old decking is still swollen with moisture from the last few months. You might end up having to remove the spacers when the old deck dries out..

Strips of 1\8 the plywood where the decking sits on the bearers but as said before decking drying out still after 6 months of moisture

this video should help

[video]http://www.youtube.com/watch?v=hkmeoYKYctw[/video]

My thoughts would be whys it rotten? How longs it been down?

i was in B+Q the other day and this fella wearing an orange and black shirt asked me if i wanted decking……
…..luckily i got the first punch in 😆

+1 for the plastic frame spacers. Any decent local hardware store will have them. The pack is full of different colour spacers. Each colour is a different thickness spacer.put spacer underneath on joists then screw down. The other wood may be swollen might not be seems to come in also rats of thicknesses these days. As asked previously would ask why they are rotten? And try and eliminate cause.

Interested in this as I have a 9 year old deck with some rot in the supporting joists. Seems a really pain to replace, for an unskilled carpenter like me anyway.

Have treated with deck stain, but for first 5 years of house being built I think little was done ( by previous owners). Do I need to install air bricks to help ventilate void under deck area – live in a wet climate near some hills/trees, so things don’t dry out quickly.

I always read this thread title as:

“Calling all deck gunners”

Would be a better thread if it was.

If its tantalised it shouldn’t rot…

If its tantalised it shouldn’t rot…

Maybe in the good old days… Modern tanalised timber rots quicker than it used to, especially if sawn ends aren’t treated.

This is why I think decking will be going out of fashion soon and people will go back to laying a nice rot-free patio instead. Can’t beat a good bit of stone for longevity.