# Forum Home Renovation Decking  merbau decking

## welshy

Hi Everyone, I am about to lay approx 200 metres of 140 x 19 merbau decking. Could you please advise what type of fastener you would recommend to use. I assume because the decking is wider than the average 90mm, that I will have fasten in rows of 3. My preference is to drill & screw as opposed to drill & nail. The decking is completely uncovered & facing north. Look forward to your feedback. 
Cheers
Welshy    :Wink:

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## Twinadventurer

Hi Welshy, 
We built a similar deck a year or 2 ago and opted to nail rather than screw. Not sure what the experts will say on this forum, but it worked pretty well. The trick was to get the right nails and also make sure you drill the correct sized holes.
The nails with a "thread" on them seem to be the way to go as they bite as they are nailed in and actually serve the same purpose as a screw. Not sure what you would refer to them in Australia as? When the hole was not big enough, unfortunately the nails became stuck when hammered in and sometimes the piece of timber had to be punched to remove it - not great for the finished product. 
Good luck with the job and we hope to see  some pics of your progress! 
Cheers
Gary

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## welshy

thanks Gary

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## UteMad

if its 19mm finish thickness you could go type 17 square drive 12g 65 stainless countersunk deck screws or 
65 or 75 mm 14g bugel batten screws  in either gal or stainless .. 2 per joist
or 65mm or 75 mm titadeck nails if nailing 
cheers utemad

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## cell1

I read somewhere that Merbau will stain black when in contact with metals. Can someone confirm whether this is true and if so what type of metals will cause this staining.

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## welshy

Thanks utemad, much appreciated. I was told that being 140mm merbau I should use 3 fasteners per board, I will take your word for it that I will only require 2 per board. How far from the edge should I place the screws. 
Cheers
Welshy  :Roll Eyes (Sarcastic):

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## UteMad

If you look at the 140 board divde it by 4 it will show you approx 30 - 35mm is about right..30 if your going 12G and more like 35 if your going 14G as the head is larger..
14G give you a jetty look but butt joins will require double joists as you cant put 4 into the 1 joist at a butt join .. 3 screws would be if your going 10G 50mm std deck screws 
this is also and option but wont look so good.. we tend to go 14G bugels when going 140's as that is usually the look we are after but it does take longer and cost more 
cheers utemad

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## UteMad

> I read somewhere that Merbau will stain black when in contact with metals. Can someone confirm whether this is true and if so what type of metals will cause this staining.

  yes it does cause a blacky blue carbon looking stain.. not only merbau though it happens with most hardwoods when bare uncoated.. metal furniture and anything metalic can cause it and it only needs a dew for it to happen.. paint tins , nails and furniture and also pot plants are all the common causes.. A good coating of deck oil is enough to curb it in most cases .. As for removal its near impossible as it soaks right into the uncoated timber 
cheers utemad

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## welshy

thanks utemad. If I use 12g screws will that eliminate the need to double joist & where there is butt joins how do you double joist? do you just screw 90 x 45 to the existing joist where you need to butt join & if you do, what method would you use to fasten? or do you double joist the entire length?CheersWelshy

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## welshy

Welshy here again. This question mainly for utemad & all other decking experts.
How do you generally fix your joists to the bearers? do you nail gun & if so what size nails do you use? or do you use uni ties? 
Cheers
Welshy   :Biggrin:

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## mlnew

I am midway thru building my deck Welshy 
I used unities made the job easy and and pleased with results 
Be sure to use correct nails when using any of the ties

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## UteMad

> Welshy here again. This question mainly for utemad & all other decking experts.
> How do you generally fix your joists to the bearers? do you nail gun & if so what size nails do you use? or do you use uni ties? 
> Cheers
> Welshy

  82mm mechanical gal nails in a paslode gas gun. to fix joists to bearers.. a bit dearer than 75's but better hold.. dont really bother with brackets as they are unsightly and there are other ways usually .. we solid block which reduces movement anyway so it would only be for uplift which doesn't happen round my way.. 
cheers utemad

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## UteMad

> thanks utemad. If I use 12g screws will that eliminate the need to double joist & where there is butt joins how do you double joist? do you just screw 90 x 45 to the existing joist where you need to butt join & if you do, what method would you use to fasten? or do you double joist the entire length?CheersWelshy

  
it depends on how well your joist set out is ( square to boards ) 
Once you get your decking and see the sizes you have a few options..
if using 90 x 45 joist you can use a few 90 x 70 if you can plan the joins over say 3 joists or so or you can double up 2 joists side by side.. you could block along side and fix on with bugel batten screws but a joist from bearer to bearer will always be a better long term solution.. these and other things are why 90mm is the most econimical size board to lay ..Its always tight getting 4 screws into a joist as you cant scew neatly with screws like nails so getting the join right in the centre is more criticle.. don't double joist the whole deck just preplan your mapping as best you can and say double 1 joist every 1/3 of the deck width or so but do it to board lengths you have to save wastage ( you will find with merbau the lengths aren't as random which makes it easier ) 
cheers utemad

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## welshy

Thanks utemad very helpful info. You have to parden my ignorance but you mentioned that you "solid block" which reduces movement. Could you explain what solid block means. 
Regards
Welshy  :2thumbsup:

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## UteMad

like noggings between studs only in the floor .. blocks that go between the joists to stiffen the structure  
cheers utemad

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