To Screw or Nail????

Morning all,

I will be replacing the deck shortly, after finally deciding on the timber to use, my latest issue is should I use screws or nails??

I will be putting down 90x19mm Northern Box hardwood boards onto existing hardwood joists (reeded side down of course). I believe that this timber is very hard and that nails guns dont like it very much, so if I was to nail, it would be by hand.

So I am prepared to use a lot of elbow grease, and just wanted to get some opinions on which method would provide the best finish, be the most durable and require the least maintenance as years go by.

Thanks

Seems like you will have to predrill whichever way you go so if you were the patient type you could use those square drive screws, they would certainly look good. Dont forget to stagger your nailing or screwing for fear of splitting the joists.

Thanks Ribot,

Had a look at those screws, and yeah, I think they would look good on the deck.

Thanks for the advice on staggering the screws, I think SWMBO needed to hear it from someone else!!!

Screws are more expensive. I also had lots pf problems with some SS square drive screws when making a garden screen - the heads kept shearing off. SOlved the problem by drilling a bigger pilot hole.

For a whole deck I'd go with the twist-shank gal nails - maily because of the cost and the look. The screws would be very obvious with two per board - not to mention expensive.

My 2c worth

Good luck

Trav

Trav, thanks for the words of wisdom. I'm going to get a hanful of the screws to do a test and see how they look.

Thanks again.

For what it is worth, I did my deck with the gal nails with the twist in the shank and they worked a treat. Of course, I still pre-drilled the holes, offset to avoid splitting. These nails also have a domed head which means that they are not a hazard to bare feet even if not driven home fully (or rather if they protrude over time due to movement)

Sorry about taking a while to say thanks, but been away for a few days. Anyway I recon that the twist shank nails will be the way to go. Now I've just gotta convince the boss that it's worth it!! She almost died when I told her how much it was!

As an alternative

On some episodes of This Old House, they used marine adhesive for the decking - held it down with a few stainless steel nails to give the glue time to dry.

I think they claimed they'd been doing it that way for seven years without a failure.

Up here in qld we have batten screws which are hex drive and come in galv. They are very good for this sort of application, particularly on large hardwood boards.

Whilst I don't know the size of the boards you could use normal galv screws. Either way pre-drilling would be essential.

Other Info- I have recently seen that black plastic (damp course) used as a wrap on the bearers and then the boards placed over. This stops water from contacting the bearers.

Also seen screws and nails in deck applications left flush with the surface, not counter sunk. Apparently counter sinking leaves a depression in which water can gather accelerating rot.

Cheers,
Conwood

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Originally Posted by Simmering

For what it is worth, I did my deck with the gal nails with the twist in the shank and they worked a treat. Of course, I still pre-drilled the holes, offset to avoid splitting. These nails also have a domed head which means that they are not a hazard to bare feet even if not driven home fully (or rather if they protrude over time due to movement)

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To a newbie, can you explain what you mean by offsetting the holes to avoid splitting? Wont that mean that the nail/screw heads aren't in a uniform line? Or, is it like a zigzag pattern that gets formed across multiple boards?

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Originally Posted by DayDreamer

To a newbie, can you explain what you mean by offsetting the holes to avoid splitting? Wont that mean that the nail/screw heads aren't in a uniform line? Or, is it like a zigzag pattern that gets formed across multiple boards?

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Yes, it forms a zigzag pattern. Such offsetting is the correct way to do it, as
shown (for example) in Alan Staines' book "The Australian Deck & Pergola
Construction Manual". (If you don't already have a copy, it's an essential
investment for a newbie, IMHO.)

If you make up a little template with 2 holes you'll be able to get each pair
of nails/screws in exactly the same place on each board, relative to the
supporting joist underneath. The zigzag pattern doesn't look too bad when
it follows the joist line uniformly. OTOH, if you were to just do it freehand,
it would look rather worse.

Stainless screws wins hands down on quality and holding power....

The trick is getting the right pilot and countersink in one (carbitool 10g is the pick at $50) and not getting the wrong screws.... Too many people are falling for the 8g or supposed 10g chipboard variety stainless screws these tend to have a weakness just below the countersink.... a true 10g screw should look like a 10g wood screw with a thickened shaft so they don't sheer off and a proper thread with a type 17 cutter in the end.....

Its the wrong screw and not the right gauge thats getting everyone unstuck with screwing......

We put in 2000 screws a deck in approx 3hrs and damage prob 5 screws and ruin 1 - 3 tips (they explode when used with impact drivers) Hardwood deck treated joists

cheers utemad

www.dialadeck.com.au

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Originally Posted by UteMad

Stainless screws wins hands down on quality and holding power....

The trick is getting the right pilot and countersink in one (carbitool 10g is the pick at $50)

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Snappy (USA) also make a great pilot/countersink bits and around $28. UteMad, does the carbitool have a shoulder that drills clearance through the decking and then pilot into joist or is it just countersink then pilot? The snappy is just countersink then pilot bit, no shoulder for clearance. Out of interest, what size pilot do you use for 10g into hardwood joists, I have used 1/8 in the past but it is not common to use hardwood for joists over here unless it is putting new boards down on an old veranda? Everything is directed toward treated pine here now, with the odd deck done with C section and self drilling wing teks, jarrah is just to expensive and it is not necessarily better.

Hi Burnsy

No the carbitool one is a 1/8 drill bit with a twin carbide tipped countersink.. For treated joists we set the drill bit just below the board and use the type 17 cutter in the screw to do the joist.... The screws will self drill and countersink into hardwood decking without even a pilot hole but the finish around the head is rough and there is too much pressure on the board which will in my opinion split the board in a few months when it dries out.....Our cheaper 10 buck pilot holers have a shoulder for clearance and a smaller pilot but they clog and can't take the speed or the amount of holes required for decking ....

cheers Utemad

Sounds like the carbitool is the same as the snappy, ask around at your tool stores you may find they are as good, I have had no problem with mine and you can change out the bits same as you say, might save you $20 per throw. I think I still have the packet around if you want the details from it.

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Originally Posted by Burnsy

Sounds like the carbitool is the same as the snappy, ask around at your tool stores you may find they are as good, I have had no problem with mine and you can change out the bits same as you say, might save you $20 per throw. I think I still have the packet around if you want the details from it.

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Are yours tungsten tipped on the countersink.... The carbitool ones cost me less than that through my supplier but not near 20 bucks...... I get near on 20 000 holes per bit but the countersinks chip in the end so i never sharpen them just get a new one.... It all comes down to whether they clog in the countersink with the hardwood .....This costs a lot of wasted time unpicking them thats why i switched to carbitools they tend to stay clean.... The square drive bits are the pain you never know how many will explode on a job so generally buy them by the dozen to be safe..

cheers utemad

We're in the process of building a deck and have gone with 50mm 10g stainless steel screws (square drive, of course!). I bought them on ebay for $370 (including postage) for 2250 of the buggers! FYI the whole deck is ironbark - above and down below.

I'll let you know how this goes, but they do look really good - I think the nails look a little odd. Just my personal opinion.

Lotte

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Originally Posted by LotteBum

We're in the process of building a deck and have gone with 50mm 10g stainless steel screws (square drive, of course!). I bought them on ebay for $370 (including postage) for 2250 of the buggers!

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That sounds pretty good. (I got my less-good 7gx65mm the expensive way
by normal retail.:doh:)

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FYI the whole deck is ironbark - above and down below.

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Fantastic. Did you use grey or red ironbark decking? I only used a little bit
of grey ironbark in my support work, but found I loved working with it.
When you said "down below", did you mean joists & bearers? If so, did
you use green ironbark, or dry?

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I'll let you know how this goes, but they do look really good - I think
the nails look a little odd. Just my personal opinion.

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I like the look of the screws too, and they're easier to re-tighten down the
track if necessary.

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Originally Posted by LotteBum

We're in the process of building a deck and have gone with 50mm 10g stainless steel screws (square drive, of course!). I bought them on ebay for $370 (including postage) for 2250 of the buggers! FYI the whole deck is ironbark - above and down below.

I'll let you know how this goes, but they do look really good - I think the nails look a little odd. Just my personal opinion.

Lotte

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Hey Guys;
If screwing, do these need to be offset too, or is it just a nail thing? I'm assuming they do, but correct me if i'm wrong.

If screwing, do you go for a wider board, or is it just a personal preference thing?

Would someone mind attaching some pictures of the look of both nailed and square drive countersink screws? We're thinking of going with the screws because we will probably have to take up part of it in a few years to lay some plumbing (as we have an idea of some future renos requiring plumbing, but nothing for sure).

Finally, i've read a few comments about the countersunk holes providing a point for water pooling and thus future rot. Is that just urban myth or is it worth paying attention to? If so, any ideas on how to avoid it? Precision countersink depth?

cheers,
Minas.

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Originally Posted by strangerep

That sounds pretty good. (I got my less-good 7gx65mm the expensive way
by normal retail.:doh:)

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The joys of Ebay. The mob I dealt with were excellent and very efficient. We gave the screws a try and they seem fine so far. I was originally worried about how big the heads were, but they seemed a good (small) size, which was great. That's the bother when you buy things online, isn't it?

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Fantastic. Did you use grey or red ironbark decking?

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It's actually mixed - some is 'grey' and some is 'red'. The grey just looks like a pale red, though. I'm very interested to see how it ends up looking. We only paid $3.20/lm for it, so I can't complain either way.

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I only used a little bit of grey ironbark in my support work, but found I loved working with it. When you said "down below", did you mean joists & bearers? If so, did you use green ironbark, or dry?

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Yes by, 'down below' I meant support work (sorry - not entirely professional at this) ie. joists, bearers, posts etc. We used green gear. It was at our place the day after it was milled. It's been quite good to work with so far - quite impressed.

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I like the look of the screws too, and they're easier to re-tighten down the track if necessary.

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That's why we chose them. We've got nails on our rear deck, which admittedly is a few years old now (and to be torn down to make way for an upcoming 45m² replacement), but they look awful. I'm a bit of a neat/control freak, hence we went for the ss screws.

Cheers,
Lotte

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Originally Posted by LotteBum

We gave the screws a try and they seem fine so far. I was originally worried about how big the [screw] heads were, but they seemed
a good (small) size, which was great.

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Small heads tend to pull through the boards as the latter swell and shrink
over time. My 7gx65mm look fairly unobtrusive, but the heads are too small
for adequate holding power. I recently went back over them all to re-tighten,
and ended up forcing some of them several mm below the surface to achieve
adequate tightness. But this is a bit too far below the surface, IMHO.

I realize now that my original pilot and counterbore holes were a bit wide.
I did some experiments at the time to try and find an optimum compromise,
but the way timber shrinks and swells over time invalidated my choices.
I was choosing the diameter so that the screw would insert reasonably
easily all the way. However, yesterday I did some more experiments with
type-17 screws and found I could use narrower diameter if I had the
patience to insert the screw partially, withdraw and clear the type-17
tip, then continue. The trick (for hardwood) seems to be to drill the pilot
and counterbore hole no larger than the innermost diameter of the screw,
and let the type-17 tip carve a helical thread path on its way down. But
this produces more crud than you'd get with a wider hole. The crud
clogs up the tip, hence the need to withdraw/clear/re-insert. It's obviously
not a realistic technique for a time-conscious contractor, but for a DIY
owner I'm sure it has to result in more secure fastening (and less chance
of pull-through as the counterbore hole is also a bit smaller).

I wonder whether the gal 10g type-17 screws have identical thread pitch.
If so, it would probably make sense to use a some of them to cut most of
the thread path inside each hole, and then insert the s/s screw last (since
the gal screws are tougher and less prone to head-strip than s/s).

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[The ironbark] is mixed - some is 'grey' and some is 'red'. The grey just looks like a pale red, though. I'm very interested to see how it ends up looking. We only paid $3.20/lm for it, so I can't complain either way.

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Hmmm. That price sounds a bit too good to be true. Was the decking
kiln-dried, or merely "seasoned". If the latter you might be looking at some
surface checking/splitting down the track. If it was green, there are even
more problems in store.

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[...] Yes by, 'down below' I meant support work (sorry - not entirely professional at this) ie. joists, bearers, posts etc. We used green gear. It was at our place the day after it was milled.

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Ah.... that's not so good. The trouble with green timber is you have absolutely
no idea what you're getting. I made the same mistake (green tallowwood in my
case), but fortunately ordered each joist length quite a bit longer than needed.
So when the giant splits started opening up at each end I was able to cut
them off. I was also "lucky" that an illness prevented me from using it
immediately, and it had to sit in the garage for several months - allowing it
to dry out a bit and reveal more of its true nature. One length had to be
discarded, being little better than firewood - but the others were usable
after I'd cut substantial pieces off the ends.

Basically, when ordering green, you can't know whether it's really F27,
F22, F17, or firewood. You'll only find out after it's thoroughly dry,
when the shrinkage can reveal the true grading. Also, in construction,
one must somehow allow for the substantial amount of shrinkage
that will occur over time. E.g: my tallowwood arrived as 200x50, but by
the time I got around to using it, the dimensions had shrunk to something
approaching 190x45.

If I was doing my deck again, I'd lash out on the extra cost of
kiln-dried F27 blackbutt for bearers/joists, and apply lots of
preservative/paint before installation to improve its durability.

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I'm a bit of a neat/control freak, hence we went for the ss screws.

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Me too.:) But sadly, we're both destined for disappointment over time.
It's unbelievably difficult to clean/weather timber adequately in the
beginning to remove the extractives before applying the finish. So the
initially lovely look doesn't last, even with plenty of TLC.

Cheers.

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Originally Posted by DayDreamer

If screwing, do these need to be offset too, or is it just a nail thing? I'm assuming they do, but correct me if i'm wrong.

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Yes, screws should be offset also. Even though you're drilling a pilot hole,
there's still some stress on the fibres as the screw goes in. The goal here
is to minimize the chances that these stresses will "link up" along the
length of the joist, resulting in long hidden splits.

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If screwing, do you go for a wider board, or is it just a personal preference thing?

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I don't necessarily perceive such a direct correlation. Screws hold far
better than nails (if inserted correctly), and that would apply regardless
of board width. Personally, I think the 86mm boards look better than
65mm (and there's fewer screws to insert overall). If using the much
wider/thicker boards (130x30?) you need to go to 14gx75mm (or maybe
even longer) screws, which are much more obtrusive. But the thicker
boards are much more rigid than the 20mm variety.

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Would someone mind attaching some pictures of the look of both nailed and square drive countersink screws?

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Sorry, I don't have a digital camera. Hopefully someone else might help
with that. However, I see we're both in Sydney (I'm on the northern beaches).
You're welcome to drop round sometime and look at mine. Send me a
private message if you want to do this.

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We're thinking of going with the screws because we will probably have to take up part of it in a few years to lay some plumbing [...]

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Good idea, but in that case make sure you don't accidentally sink the
screws below the surface. Any deeper than a fraction of a mm below,
and the timber can creep over the top of the screw, by the swelling
action of rain. Then, when you try to remove the screw, the top surface
gets damaged as the screw comes out.

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Finally, i've read a few comments about the countersunk holes
providing a point for water pooling and thus future rot. Is that just urban myth or is it worth paying attention to? If so, any ideas on how to avoid it? Precision countersink depth?

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Water will get in, no matter what. In rainy periods, there's plenty of
opportunity for water to seep in between screw and timber by capillary
action. This is all just another reason why it's imperative to choose an
extremely durable timber for your decking - because then you don't need
to worry about this sort of issue. Trying to save money by choosing a less
durable timber is just false economy.

Cheers.

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Originally Posted by strangerep

Small heads tend to pull through the boards as the latter swell and shrink over time. My 7gx65mm look fairly unobtrusive, but the heads are too small for adequate holding power. I recently went back over them all to re-tighten, and ended up forcing some of them several mm below the surface to achieve adequate tightness. But this is a bit too far below the surface, IMHO.

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You're scaring me. Big time!! :C

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Originally Posted by strangerep

Hmmm. That price sounds a bit too good to be true. Was the decking kiln-dried, or merely "seasoned". If the latter you might be looking at some surface checking/splitting down the track. If it was green, there are even more problems in store.

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It's kiln dried. Some of the boards are somewhat flawed (hence they were cheap) and we won't use them, but 95% of them are great.

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Ah.... that's not so good. The trouble with green timber is you have absolutely no idea what you're getting. I made the same mistake (green tallowwood in my case), but fortunately ordered each joist length quite a bit longer than needed.

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It was green when we got it but it has sat around for quite a few weeks now. From the research I did, timber only remains 'green' for a couple of weeks. It was actually quite dry to cut and there was some fairly out there twisting which we had to straighten out using noggins.

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If I was doing my deck again, I'd lash out on the extra cost of
kiln-dried F27 blackbutt for bearers/joists, and apply lots of preservative/paint before installation to improve its durability.

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Man! Where were you before I ordered ANYTHING? :C

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Me too.:) But sadly, we're both destined for disappointment over time. It's unbelievably difficult to clean/weather timber adequately in the
beginning to remove the extractives before applying the finish. So the
initially lovely look doesn't last, even with plenty of TLC.

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Tell me this. The decking we've bought has 'sat around' in our garage for a couple of months now. Will we still need to leave it to 'weather' for 6 weeks after we install it, or can we clean and oil it straight away?

Lotte

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Originally Posted by LotteBum

You're scaring me. Big time!! :C

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Nah, people do this all the time. Just insert your type-17 s/s 10g x 50mm
with a driver than has a torque control. Do some experiments yourself first.
Oh, and get a can of WD-40 or equivalent - the one that comes
with a narrow plastic tube nozzle. Use a very brief squirt down each
hole as a lubricant before you drive each screw.

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[The ironbark] was green when we got it but it has sat around for
quite a few weeks now. From the research I did, timber only remains 'green'
for a couple of weeks. It was actually quite dry to cut and there was some
fairly out there twisting which we had to straighten out using noggins.

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Consider that proper kiln-drying involves keeping the timber in an
extremely well-ventilated fan-forced shed for many months. Even if you
left your timber in the garage for a year or two, it probably wouldn't get
as dry as such kilns achieve. It's probably too late now, but the end grain
should have been well sealed/painted before installation, because they
dry out faster than the rest of the beam, and that's what causes the splitting
starting from the ends over time. Give them a coat of preservative (such
as stop rot - the green stuff), especially along the tops, and make sure you
use joist protectors or alcor flashing along the tops of the joists as well - that
will lengthen their life even further.

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Man! Where were you before I ordered ANYTHING? :C

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I've been right here for quite a while now.:D But don't worry too much.
You've chosen an excellent timber species, and a very good fastening method.
That's already better than a great many other decks in this country.

BTW, part of the deck that I've re-built was ironbark (probably green to begin
with, like yours). I was able to keep that section of the structure. In fact, there
were parts where original ironbark (20 yrs old) was pressed side-to-side
with newer stringybark joists (maybe 10yrs old) where a deck extension had
been built. The latter were badly rotted with white fungus, but the much
older ironbark was totally unharmed. Astounding to see the difference
side-by-side like that. Ironbark is an excellent choice of timber species.

More seriously, the poor availability of thorough information about
timber durability for exterior use is one of my pet peeves. Even Alan
Staines doesn't cover that dark, but very important, corner of
deck-building adequately, IMHO.

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Tell me this. The decking we've bought has 'sat around' in our
garage for a couple of months now. Will we still need to leave it to
'weather' for 6 weeks after we install it, or can we clean and oil it
straight away?

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OK... you definitely need to invest some more time scanning back through
the earlier posts in this forum, as the whole subject of weathering/cleaning
has been discussed many times. The short answer is that the extractives
in the timber all need to come out before you apply a finish. That requires
a combination of Sun and rain. The rain removes water-soluble stuff,
the Sun's UV breaks down other stuff and draws it towards the surface,
and yet more rain washes it away (eventually). None of this important
process can happen while your decking boards are safely stowed away
in the garage.

To test whether the extractives are out, sprinkle a generous amount
of water on a section of the timber and let it dry. If it leaves a water
mark, it means further extractives still need to come out. I.e: all the water
marks from rain need to be gone, and it needs to be fairly difficult to create
new ones.

If you're in an area that doesn't get much rain, then the weathering
process will take longer. When it does rain, it would help to get out there
with a squeegy mop and encourage the dirty water to get off the deck (rather
than merely re-drying in-place). Before applying the finish, also wash with
Napisan and Oxalic acid, as described in other posts.

Oh, and don't get depressed if the original colour all seems to be leaching
out of the timber. All that nice colour was never going to stay - because it's
soluble and/or UV-unstable. Rely on a choice of tinted finish to achieve the
colour you want, erring towards a lighter-coloured choice - because you're
going to be applying more and more over time.

Cheers.

Gee so much talk about screwing.....

keep it easy

Buy real type 17 self counter sinking 50 mm 10g s/s wood screws not chipboard....

Get a decent tungsten tipped pilot and countersink to suit 10G screws

Use and impact driver to whach them in..... Makes it easy to adjust depth ...if you get the sink to shallow the the self sinking head will do the little bit extra and an impact driver makes it a sinch to get the correct depth


cheers utemad:doh:

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Originally Posted by strangerep

I've been right here for quite a while now.:D But don't worry too much. You've chosen an excellent timber species, and a very good fastening method. That's already better than a great many other decks in this country.

More seriously, the poor availability of thorough information about
timber durability for exterior use is one of my pet peeves. Even Alan
Staines doesn't cover that dark, but very important, corner of
deck-building adequately, IMHO.

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That book has been my bible, but there are various areas where more information would not have hurt. For instance, like you mentioned, hardwood species is an extremely important factor, and I think most would agree that fastening is of utmost importance as well.

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If you're in an area that doesn't get much rain, then the weathering process will take longer. When it does rain, it would help to get out there with a squeegy mop and encourage the dirty water to get off the deck (rather than merely re-drying in-place). Before applying the finish, also wash with Napisan and Oxalic acid, as described in other posts.

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I'm in Brisbane - we had our first lot of decent rain since 2004 last week. And the deck is positioned in such a way that it doesn't get much sun at all through winter. I see what you mean about the water though - I accidentally sprinkled some water on part of the deck today and I now understand what you mean.

[/quote]Oh, and don't get depressed if the original colour all seems to be leaching out of the timber. All that nice colour was never going to stay - because it's soluble and/or UV-unstable. Rely on a choice of tinted finish to achieve the colour you want, erring towards a lighter-coloured choice - because you're going to be applying more and more over time.[/quote]

Ok, yet ANOTHER question... as I stated earlier, the decking is Ironbark - mixed colours (various shades of it - red, grey & brown). Will they all eventually just be kind of grey (ie. the same colour)? What stain would you use in order to restore the Ironbark colour in time?

Thank you so much for your advice - I've taken everything onboard. This is just our 'little' deck - we will be building a 45m² deck to the rear of our house sometime this year, and I will endeavour to refer back to your information (which I have saved to my desktop).

Cheers,
Lotte

P.S. You really ought to write a book. Seriously. :)

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Originally Posted by LotteBum

Ok, yet ANOTHER question... as I stated earlier, the decking is Ironbark - mixed colours (various shades of it - red, grey & brown). Will they all eventually just be kind of grey (ie. the same colour)? What stain would you use in order to restore the Ironbark colour in time?

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It will all go shades of grey if you apply no finish at all.
Once that has happened, you really need to re-sand back to bare timber
and start again if you want a nice colour. But weather it properly
initially, and apply a decent finish. Experiment with Spa-n-Deck if you
haven't already - others in the forum speak of it favorably, though you
need to apply more coats than recommended by the manufacturer.
Someone explained this recently - check back through earlier threads.

One more tip about weathering: take several small offcuts, representative
of the various different shades. Soak them in a tub of water for an
hour or two, agitating occasionally and turning them over if they float.
The water will go horribly dirty. Rinse them off, and repeat with a fresh
tup of water. Then allow to dry thoroughly. You'll be surprised how much
paler they are. That's the colour you need to achieve in the weathering &
cleaning process for best results: - it means that the maximum amount of
water-soluble extractives have been removed before applying the finish.
(I.e: keep the offcuts for later reference, together with some samples of
the original unwashed stuff.) Napisan will also help a lot.

If you make several such (cleaned) offcuts, you can also test various tints
of finish on them to see what happens as you apply several coats.
Try 3-4 coats of the red cedar tinted stuff and see if you like it. :)

I found this website (via ebay) for screw supplies, greater discounts apply for bulk purchases. However it appears they have a fair supply of type 17 10G square drive screws. different tips, and heads

Any ideas regarding product numbers, and best type for decking.
http://www.metalbythemetre.com/index...n=page&name=10

I have no association with this company, but their prices on ebay and for 1000 lot purchases are way better than what I could find retail in my local area.