Decking Frame

Bluefoam

I'm in my house for two years now, and its about time I did something about the garden... It seems to have stopped retaining water and I need to sort out an area that I can place chairs and a table...

I was going to do paving (preferred option) but due to budget, I'm looking at composite decking...

The garden is 10m x 4.5m. Decking will be 4m x 4m with a 250mm pebble bed around. Walls on 1 side and rear, fence with concrete posts and timber panels on one side.

Under the garden is hard packed stuff and builders rubble... Rather than dig a number of 700mm holes with great difficulty, can I use another method? I don't see much movement happening in the soil and I'm not entirely keen on timber cemented in, either for rotting in the Irish weather, or even that I might replace it with slabs in the future and will have to break down the concrete...

Was looking at some of these (below), but would be grateful for any input. I know I'm looking at something that seems extreme, but I know I'll have difficulty getting down into the earth and even a giant arbour will struggle.

ted1

Why composite?

move been talking to several people who decks professionally and they all advise against composite their main reason is that the sun frame is still wood and will need to be replaced so the extra cost isn’t beneficial

paving can be cheaper. I did a Porcelain patio last summer and it cost less than what decking would have cost

Bluefoam

https://www.boards.ie/discussion/comment/119758267#Comment_119758267

It ages better and takes less maintenance. I've specified plenty of decking on commercial projects and have developed a preference for composite.

In fact I'm looking at replacing some timber decking for my dad soon as it has weathered and needs attention.

ted1

https://www.boards.ie/discussion/comment/119758290#Comment_119758290

the sub frame doesn’t age any better ;) and is still slippy in the wet

I’d go paving or porcelain

NewClareman

I'm considering using composite decking as an alternative to paving but I wouldn't consider a wooden sub frame under any circumstances. I've seen first hand how it rots, even when properly maintained.

Have you investigated any other options for the sub frame, such as aluminium or recycled plastic? I've only started looking at these, but aluminium looks promising. It might be possible to mount the subframe directly on the ground, given it's so compacted. With a small number of anchor points, for safety. I've seen subframes placed on 1/2 blocks, in a mobile home park, held down solely by weight.

Good look with your project and you might let us know how you get on.

Lumen

A timber frame is fine if suitably constructed and protected, although the effort to do so might make alternatives preferable.

What's with the 700mm holes? Are ye putting a house on it?

Bluefoam

The internet recommends 700mm... What should it be?

Lumen

https://www.boards.ie/discussion/comment/119759093#Comment_119759093

I dunno. Is wind lift a problem? Decking and frame is bloody heavy. I'd probably just use some kind of helical ground screw if I was bothered. Concreting in seems excessive.

Bluefoam

https://www.boards.ie/discussion/comment/119760230#Comment_119760230

This is what I'm thinking, in theory the deck should hold itself down by its own weight. Some very simple footings would help separate the frame from the soil and help manage rotting...

RainInSummer

I used a bunch of these to support the composite deck I built.

https://www.rynogroup.co.uk/components/rda/

Laid directly on compacted ground that had a deck sitting on it for 10+ years already.

The composite stuff I have is not slippy when wet, even after three+ years of not being touched by a brush or any sort of cleaning product.

Time will tell if the wooden subframe gives way. They are 6x2 southern yellow pine in from the states with an MCA treatment. I was initially going to go for an alu sub frame but the expense was already through the roof!

RainInSummer

Oh and on the wind thing, you'd only really ever have to tie down a deck if you had a lot of space underneath. One example in Waterford I have seen is on a split level house, deck comes out from a bedroom and into space, under which is enough room to house a garden shed, 2.4m high at least. The wind gets under that alright.

Composite is heavy. At ground level with a skirt around the edges there's no hope of it lifting.

Bluefoam

https://www.boards.ie/discussion/comment/119766422#Comment_119766422

I would consider using these on floating paving slabs...

RainInSummer

I stuck some on blocks or whatever pavers I had lying about when I needed to get more height.

They're expensive but the time saving is huge. Just plonk them down and twist them to height. Spirit level on the joist and you're level in no time.