Screw or Nails ( How Many in each Board )

[srohara]

Hi

I am building a new deck and i am using 65 x 19 Merbau decking.

1. I want to know if i should use nails or screws to fasten it to my hardwood joists.
2. How many screws or nails should i use per board (width ways)
3. What size nails or screws should i use.
4. Can i use a nail gun if nails are used or should i pre drill
5. What size gap should i leave between boards. the boards are 3.5yrs old Have been laid before

Any advice would be great.

Thanks
Scott

[rod1949]

Re "the boards have been laid before" You have probably already answered some of your questions as you should be able to determine if they were nailed or screwed and how many were used.

Me, I would use galvanised nails, 2 per width to help prevent cupping. The nail length should be 2 1/2 time the thickness of the flooring.

You would only need to pre-drill if nailing right on the end of the board.

The gap can vary from the thickness of the nail you use but I would go wider than 10mm.

[russall]

I'm using 2.8x50MM Titadeck nails and am having to pre-drill EVERY hole! if I don't they nails tend to bend about 20mm into the hardwood joist.
A couple of the Joists around the stairs are about 30 years old whcih I have reused from the original deck, the nails won;t even begin to go into these evern with a 2.5m prederill

I could just be crap with a hammer

[remonyan]

I watched a Mitre 10 video clip that show you how to build decking, that guy was using a nail gun and put a big nail between boards to hold the gap when he was nailing them down. He also only predrill the end of the boards. From a Mitre 10 decking plan, it recommends a 4mm gap. Rod, 10mm sounds too wide, maybe?

Ray

[mako]

If you can hire a nail gun and compressor life will be a lot easier. Use 50mmx2.5mm (or there abouts) with "screw shank', as opposed to ring shank which are designed for pine joists. Either galvanised or if you can afford it stainless steel (which look better). As said before 2 per deck board over each joist. Pre drill all ends and joins. if hand nailing the whole thing you will nedd to pre drill all holes especially in hardwood joists. 4-5mm gap. Any smaller and too much grit biulds up in the crack, any bigger and small children will fall through. Good luck !

[russall]

Oh yeah, I made me 4 spacers by grabbing 5cmx5xm bit of plywood and driving a nail through it. Works really well, especially as most of the kwila I'm using is far from straight I can just drop the spacer against A, push B into place, drill and nail.

I chose not to use a nail gun as from what I understand you can do a better job by hand and teh nails are better too. Plus unless you own a nail gun you have a time limit to do teh job by otherwise kennards make more $$$ from you.

[mako]

It will generally be neater hand nailing if you are inexperienced using a gun and like russel said you will be on a time limit. For spacing i use two chisels which are 5mm thick. put one in for the spacing and use the other to prize the next board up tight, especially if it is bowed. Then put your nail in.

[srohara]

Thanks for the replies, so everyone would just use nails instead of screws. I was thinking of using stainless steel screws but was not sure. Has anyone used screws on there decks. If i use nails i think that i will do it by hand.

[silentC]

Using a spacer is not a great idea in my opinion. It's too easy for small errors or discrepancies in board widths to stuff you up and it will look terrible.

Here's what I do:

1. Nail down the first board all the way along the length of the deck - start from the outside board. Use a string line to make sure it is straight.

2. Work out the spacing for 5 boards - 65mm plus the gap you want (5mm is good) and measure out from the first board and mark the joist at each end of the run. Repeat this for every fifth board.

3. Ping a line with your chalk line across each joist so you have a mark for every fifth board. Nail down these boards to the lines.

4. Cut all the boards for the gaps and lay them in place. Make yourself a bucket full of hardwood wedges and use these to set the gaps for all four boards at each joist in turn - nailing down as you go. Set the wedges between the four loose boards and wiggle or tap them until the gaps are even. You can eyeball the gap, or check it with a spacer if you're fussy. I eyeball mine.

There's no way you can go wrong. Work the gap so that you don't have to rip the last board if you can.

[woodcutta]

Scott

1. Use Stainless Screw nails - buy them in coils for a coil nailer and strip them off the plastic - They work out about half the cost as the same nails loose.

2. Drill every hole. If your a good shot you can use a coil nailer to shoot into the hole you have drilled. I'm not a good shot

3. If the decking is not dry, dont leave any spacing. Lay out about 8 to 10 rows, clamp tight and then mark and drill the holes. Six months after the deck has been down there will be a 2 - 3 mm gap.

4. Stainless steel screws are good in treated pine but are weak and sometimes shear off in hardwood. DAMHIKT

woodcutta

[mako]

Exactly what i do silentc. Just i use eye sight and my chisels to get the gaps right. Good advise

[remonyan]

If I have to drill every hole, then how big the hole should be - 2mm?

Ray

[silentC]

Exactly what i do silentc. Just i use eye sight and my chisels to get the gaps right. Good advise

A chippy mate showed me the wedge idea. I've got a bucket of about 30 or so. If there's two of you, you get one guy on the wedges and another on the coil nailer. It's amazing how quick you can lay it. It takes a fair bit of stuffing around to set up, but it's well worth it on a big deck.

[Burnsy]

If I have to drill every hole, then how big the hole should be - 2mm?

Ray

Hole should be a little less than clearance so it is not just the head holding the board down. Don't drill deeper than the decking board if you are laying onto TP, just nail straight into it.

Woodcutta has some good advice regarding buying coil nails and stripping them off the coil to use by hand. Make sure they are screw nails and not ring nails. The ring nails tend to rip a hole in the pine and don't hold as fast as the screw nails in my experience. Screw nails are also much more likely to be successful if you are shooting them into dry boards, the process that rings the ring nails can make them very weak and the last batch I had folded up in the gun three times out of four where the rings had weakened them (they are still in the shed). I bought screw nails in there place and not one of them folded.