# Forum Home Renovation Decking  Decking Screw Problems

## ::Dan::

Hi, 
I've just started laying 90x19 Merbau decking and I'm using Buildex, Stainless Steel, 316 grade, 10 - 8 x 65 square drive screws. I'm counter sinking and pre drilling with a 3.5mm bit. 
So far in the first three boards, I've had two of the square drive holes bore out, and two heads snap off. I'd heard that the 'Bunnings Buckets' are terrible screws, but I thought that being SS they'd be decent. Can anyone recommend better screws? or is there something I could be doing wrong? The drill I'm using to drive the screws in is meant to have two speeds, but the faster setting is broken at the moment so I'm using the slower, higher torque setting. Could I be driving them in too slowly? 
Cheers, 
Dan

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## dazzler

Hi Dan 
Why not use nails.  Good old fashioned nails.  Just like grandpa used  :2thumbsup:  
Bang bang bang, job done, open a beer  :2thumbsup:

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## binda

I haven't used SS deck screws but I know from past experience using SS screws in general that when the screws heads are twisting off, it means your pilot hole is still too small.

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## shaneos

Dan, 
I have just completed my decking, therefore i am an expert. LOL just kidding. I followed the advise of a few other members, and got the 10g 50mm screws. http://www.tradeproducts.com.au/10g_..._square_drive,, I don't think these are 316 but maybe wrong. I was driving these into treated pine joists and did not strip a head, or break a screw. (all pre drilled) 
but i did make life easier on myself by purchasing a Impact Driver. I got a well priced Ryobi from bunnings for $159. I believe this baby made all the difference. I tried the dewalt once and it had to much bite. 
I would suggest looking at these areas.

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## ger

I used a tool that screws the hole and
counter sunk the holes at the same time
over 3000 srews inserted not one  problem
 think it was called deckmate 
 Great tool only cost me about $30

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## oohsam

Dan, 
What you are experiencing, as other members said, is a problem with your pilot hole, or you are screwing them in too fast/hard. 
If you want to test this, screw it half in, and touch the screw, you will notice its very very hot.  
If you want to minimise stripping the head off, drill a larger pilot hole (please provide what drillbit you are using to predrill so we can ensure you are using the right size) and use an impact driver.  
Ryobi sell them for 130 bux or so, and they are pretty good. 
When you drive the screws in, try blipping the driver, dont go in one continus shot. If you have hardwood decking and treated pine joists, dont drill through the TP, just the hardwood.  
Cheers.

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## jba

Hi Dan, 
I agree with Shaneos. I used macsims Stainless Steel square drive 10g 50mm type 17 screws for my deck and it works great. I used a smart-bit, from macsims again, to pre-drill my 90x19 mm Merbau boards and 90x45 TP joists. 
I did not get my screws from Bunnings, though. I got mine from an Spillers Industrial Supplies in Penrith - I'm from that area in Sydney. I talked to the guys there and asked what size smart-bit I'd need and they did recommend the proper one for the screws. 
Maybe the guys from Melbourne on this forum could recommend a place where you could get proper decking screws. 
Cheers, 
Jerome

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## oohsam

Not sure what you mean about 'proper' decking screws. !! eheheh.. 
I've tried a few different brands and am currently building a deck with the bunnings screws. They seem to hold up fine. Shredded 2 screws out of 400 so far, so I'm assuming its your technique and not the screws.  
I would be almost 100% sure your pilot hole is too small...or non existent.  
Cheers.

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## ricey250

Hey Dan, just finished my deck using the same screws except mine were 12-10g and I didn't snap or strip a single one.
I was using a 4mm pilot hole which is standard for 10g screws I'm pretty sure.
I also dipped the tip of every screw in linseed oil which seemed to help.
This may seem tedious but I reckon it made all the difference, I've done 2500 screws and still going strong!
Do the screws have type 17 tip? if not this might also be contributing to the problem. 
cheers ricey.

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## ::Dan::

Thanks very much for the advice everyone. I stepped up to a 4mm bit (I had been using a 3.5) and I realised that I had also been only drilling through the merbau, not into the TP joists. It seems to be going fine now. 
Another question though, the Allan Staines book recommends driving the pairs of screws at an angle diverging down away from each other into the joist, sort of like this /   \ . I had been thinking it would be better to drive them in at the opposite angle, converging down towards each other, sort of like this \   /. 
The /   \ shape would seem to allow for cupping as the arc of the screws is already in the same direction that the board would want to move if it was trying to cup, whereas with the \   / shape, each screw would seem to be resisting the natural arc of cupping? 
I'm doing it Allan's way because I'm sure I must be missing something, or just thinking about it incorrectly, but I'd like to hear any reassurance. 
Cheers, 
Dan

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## GraemeCook

Nice to see that you got helpful advice, Dan. 
Ricey's suggestion to dip the screws in oil is a good one - cooking oil is just as good as linseed here.  I just tie a small sponge to my drill/driver, moisten it in cooking oil, and then rub each screw against the oil.   Lubrication halves the effort in driving screws. 
Cheers 
Graeme

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## shaneos

Dan, 
I believe Allan Staines books talks about driving nails in at angles, and also off centre from each other as the two methods. I am not sure he means screws. If you try and drive them in at angles is not a good idea.

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## ::Dan::

Shaneos, it definitely does refer to nails only, I just assumed it would be the same for screws. Is there a reason it's not good for screws? If so I'd like to know because I don't want to continue screwing on an angle if it's bad for the deck (I've only got a few boards down so it's not too big a deal to re-do them). I'd love to just do them straight, as the heads would look a lot better perfectly parallel with (and just below) the merbau, and it would be a lot easier to get the depth perfect. 
Cheers, 
Dan

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## ricey250

Hey Dan, it's not that it's bad to do it with screws, just that the thread on the screws is enough to stop them pulling out of the joists if the boards cup.
Don't worry, the ones you've done on an angle will be fine.
I wouldn't bother continuing to srew them in on an angle though as they won't countersink flush, as you've probably figured out by now, and the 65mm screws you're using will get plenty of bite, so I'd be going straight in from now on.
Just be careful not to pre-drill too far into those TP joists, a little bit is ok but I wouldn't be going the depth of the whole screw..... Oh yeah, and give the linseed or cooking oil a go, you will notice the difference :2thumbsup:  
Cheers, 
Ricey.

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## shaneos

Dan, 
Well i am no expert as i have stated, but i consider myself useful and have never ever ever heard of drilling screw in at an angle for decking.... I think you are on the right path though with the other guys suggestions. Use your pre drill counter sink, you should not need to pre drill into the treated pine as this is soft, however if you do a little no one will care. And drive all your screws in and you will be laughing. 
You really can not go wrong, As i have said in my post about my decking my regret was not getting a smart bit and having the countersink preset so every time i did my pilot and countersink in one go, it gave you different depths.  
In the "BOOK" he refers to nails requiring this as they have a tendency to work there way out due to movement of the decking from shrinking etc etc. etc. 
You will need to upload some pictures for us to see how your going with your project.!! 
Good luck with it mate. 
ShaneO

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## ::Dan::

Thanks a lot for this info guys (even if it does make me feel a bit stupid for having angled my screws for no reason up until now). Luckily the pre drill bit I've been using is a fair bit shorter than the screws so hopefully I'm not pre drilling too far into the TP. It's a great relief to know that I can drill straight now, it'll look a lot cleaner. I'll start dipping the screws in oil tomorrow too. 
I'm now thinking though, when I've finished the rest of the deck, is it a good idea to take out the screws I'd already done on an angle and put them back in straight or would that compromise the joists with too many screw holes? 
Cheers, 
Dan

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## GraemeCook

I would not replace any existing screws - the holes could fill with moisture and eventually precipitate rotting. 
Cheers 
Graeme

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## UteMad

screws will find the old holes anyway and loosen as the two holes become one bigger one  
cheers utemad

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## billy74

I think you will find that you will have problems when you use a low quality screw. 
All I use now are Spax screws. They have a Spax-D screw specially for decking and it comes in 304 and 316 stainless steel. 
I can usually go into hardwood without predrilling and never have any problems. These screws never snap or burr out and never split the timber. Also they make the job so much quicker and easier and hold so well. 
They have a website at Spax Screws. 
So try getting a high-quality screw like Spax and see how you go.  Admin note, Billy 74 is not affiliated with this company.

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## barney118

The smart bit is a good investment, pilot drilling and countersinking in one go.

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## jkirky

Anlding screws is not wrong as such... In fact it can be considered a sound practise for anchoring...  
However common practise tells us that it is generally unnessesary and screws will anchor fine if kept square to the board. Also, angled screws can look a little untidy (depending on how much angle has been applied). But certainly dont be convinced that angled screws are "wrong"...

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## Bloss

> Anlding screws is not wrong as such... In fact it can be considered a sound practise for anchoring...  
> However common practise tells us that it is generally unnessesary and screws will anchor fine if kept square to the board. Also, angled screws can look a little untidy (depending on how much angle has been applied). But certainly dont be convinced that angled screws are "wrong"...

  Ah well each to their own I suppose, but angling for screws is definitely _not_ good or 'sound' practice as has been mentioned above. As you say it is unnecessary as the additional friction of the screws provides sufficient holding power, but more importantly the screw head should be recessed to sit flat into the timber be using a countersink bit of the self-countersinking designs. 
An angled screw on a deck places a section of the round edge of the head above the countersink as a trip hazard or if sunk so that high section is flush it creates a water trap. So unless there is some specific problem that needs an angled screw to be resolved (and there are some) the rule should be that a screw should be sunk perpendicular to the work face - applies in steel work too. Otherwise it is 'wrong' to angle IMO.

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## Pickled dragon

With 140mm w x 25mm Merbau decking using 10g x 50 bugle screws, How many screws should be used across the width to stop bowing?  
Cheers

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