Decking Qs (one for the MedwayHandyMan?)

[dmc]

Ok, I'm getting sorted to build this deck now the days are getting longer. A few Qs before I order the wood...

Deck is to be 5.5m * 3m ish. Covering a existing concrete area that slopes down to one corner and isn't particularly flat at all. Plan is to build a frame that sits on the concrete at the front and them is supported with a few small brick piers towards the back. Height of the piers at the back will be about 3 bricks or so. Given SWMBO wants a pergola on top of this I'm thinking of building small piers with a slab on top at the points where the 6 pergola uprights will be and then standing the pergola on these. This means I don't need to faff making the pergola uprights all different lengths (assuming I get all the pads level :)). Will then sit the decking frame on top of these as well - with some intermediate supports for the frame as needed (pergola uprights will be 1.8m appart).

Most places seem to suggest 150x50 joists. A couple say 100x50 will be ok. Assuming I go with 150x50s how frequently will they need supporting?.

Similarly, how frequently do I need to place the joists? I'm probably going to go with

which have a finished sized of

34mm x 120mm so reasonably thick boards. Seems recomendations are from 400mm to 600mm centres. Any one with experience suggest what would be best? I don't want to end up with something bouncy :) Noggins every how far?

To build the frame I'll use the turbo golds that Dave recommends - drive them in with no pilot hole? Or would nails be a better bet?

Finally, once this thing is build any recommendations for coating it? Or best left alone to age? It's all pressure treated softwood...

Cheers,

Darren

[meow2222]

2x4 or 2x6? 40cm or 60cm spacing... there's no right answer, all those will work. Just a question of how much you want to spend and whether you can tolerate a tiny degree of movement under load. With 2x4 at 60cm centres you'd notice it, 2x6 at 40cm it feels rock hard and could support very heavy loads.

NT

[Jules]

fun :-)

For floors here houses here seem to use 6x2" joists (which I think is about 150x50mm, no?) on 16" spacing with supports about every 10' or so; I'd be tempted to use the same for a deck just so I knew it'd hold a bunch of people and/or other stuff.

(our basement here is actually the above but with 6x6" cross-supports at the ends of the 10' runs, which are in turn on concrete pillars every 8' or so - but then that has the weight of the walls, upper storey and roof to contend with too, so is probably overkill for a deck :-)

I'd go with the 16" (i.e. 400mm) I mentioned above, just so I know it'd work. I can get 6x2" for 30c/foot (what, 20p?) here, so it doesn't exactly push the price up a whole lot to use 16" spacing vs. 24".

We've got alternating diagonal braces between joists here (if I'm getting my terminology right, a noggin always runs horizontally between joists, not diagonally?). There's a brace every 2' or so (both sides of each joist) which alternate top-bottom and bottom-top. Each brace is a piece of

4x1" (with the 4" in the horizontal plane).

Works very well, but I suspect that might be overkill for a deck which won't be loaded as frequently (although it will be more exposed to the elements...)

Perosnally I try and use screws for everything I build (and always drill pilot holes) - but I think you could get away with nails for anything horizontal as unlike the vertical portions they're less likely to work loose over time.

I'll leave that for the experts - but await reply with interest, as building both a deck and some fencing around the front lawn using the same material is on the cards here...

cheers

Jules

[dmc]

Ok, so 2x6 at 60cm would be pretty solid I'd imagine. Works nicely with

3m deck :) Piers/supports at similar distance?

A bit of movement is ok. A bouncy deck not. Cost isn't a real issue tbh - just trying to cut down on the amount of wood I need to lug all the way around the house :)

Darren

[PeterCB]

Not answering your questions, but can I recommend if you don't already have on, that you invest in a 10" sliding mitre saw. I did the first half of my deck with a combination of circular saw, jig saw and old fashioned wood saw, and it was a chore. Half way through I decided to invest in the mitre saw and the whole job became a walk in the park. About 120 quid on ebay ISTR, only problem might be finding somewhere to keep it afterwards, takes up a hell of a lot of space in my shed.

[matthew.larkin]

FWIW, I used 2x6 at 40cm, supports at 180cm centres, noggins staggered across at 90 deg approx 18cm too. Thats for a 4.8m x 4.5m deck.

Of the four corner supports, two sit directly on existing flags (put in by competent builders a few years ago) in metpost supports bolted into the flags. The other two were postmix-ed in place so there's zero movement. Other supporting posts along the sides of the frame and in the middle were on padstones bedded onto hardcore and sand.

Its rock solid (well, it was when I left it!!), no bounce at all (I've got 4 boys, and they test it for these things!).

I may have overkilled some of it, but it does the job!

Matt

[dmc]

Hmm... I have been looking at them thinking they would be handy but I'm not sure I can justify it. Maybe I'll take another look.

SWMBO is already looking at the pile of screws, drills and assorted tools that are collecting in the conservatory and asking when the deck will be finished :)

Darren

[TheScullster]

"PeterCB" wrote

Saw a program many moons ago about a guy who took his eye off the ball using one of those things - lopped his hand clean off. They managed to stitch it back on and regain a lot of function, but his wrist looked a mess. Not saying they are any more dangerous than other power tools, just need suitable respect.

Phil

[The Medway Handyman]

I use mainly 150 x 50 & support any span over 3m. If I have to use 100 x 50 to get under a door threshold I support it every 2m. Both at 500mm spacing.

You won't get any bounce with 150 x 50 at 500mm spacing I use noggins at 1m spacing, but alternating odd/even/odd etc. So with 3m joists I'd use 3 in the first row, 2 in the second, three in the third etc.

6 x 90 turbogolds deffo. No pilot hole, decent 14.4v driver will put then in, or muchos better an impact driver. Two will give you a really strong joint. Easier to pull a sailor off your sister etc.

It will last OK even if you don't coat it, but it will fade to that silver grey like fence panels do.

I'd leave it a fortnight to even out the moisture content & colour, then a coat of decking oil.

[The Medway Handyman]

Quite common to have parties on decks, could well have 30+ fat bastards on it.

[The Medway Handyman]

Aldi have a good one for £50 from time to time. Failing that, make up a sawboard.

They have no idea about these things do they?

[dmc]

I have a couple of sawboards made up in different lengths. Fantastic things - anyone who has a cicular saw should have one!

heh :)

Darren