Screw or Nail Decking

[corey]

I am replacing the boards on the deck of an old queenslander. The joists are 50mm by 100mm and at 650mm centres. I am using 145mm hardwood decking as the replacement. Is it better to screw or nail and if so what size/type of screw or nail. What is the best method at the joins as I only have 50mm to play with?

[seriph1]

Hi Corey and welcome to the forum. You should find a HUGE amount of info here and a lot of folks willing to help.

The joists sound fine and are pretty much what most of them were done with I believe. Personally, I would nail the decking and predrill the ends to avoid splitting. A nail gun is a godsend in this application. Galvanised or stainless steel nails are what you will have to use as plain steel will rust pretty fast I believe. 50mm is the go I think (check with others), depending of course on your decking's thickness. If nailgun-ing them, I also think the nail heads should "just" break the surface NOT go right in. Decking nails have a rounded over head. Do you know the species of hardwood and is it decking timber or flooring? Pics of the home if you have any please

[corey]

Hi Corey and welcome to the forum. You should find a HUGE amount of info here and a lot of folks willing to help.

The joists sound fine and are pretty much what most of them were done with I believe. Personally, I would nail the decking and predrill the ends to avoid splitting. A nail gun is a godsend in this application. Galvanised or stainless steel nails are what you will have to use as plain steel will rust pretty fast I believe. 50mm is the go I think (check with others), depending of course on your decking's thickness. If nailgun-ing them, I also think the nail heads should "just" break the surface NOT go right in. Decking nails have a rounded over head. Do you know the species of hardwood and is it decking timber or flooring? Pics of the home if you have any please
Thanks steve. The decking is 145mm * 19mm Vitex from New Guinea (Dont go into the rainforest thing, already copping it from the wife!!) I was looking into buying a nail gun and compressor. I only need it for around the house stuff so would a compressor and equipment from the discount auto shops suffice. What sort of nail gun would i need?

Corey

[Gaza]

i would go for the screws as hardwood does tend to split when nailed by gun. Also check if 19mm decking is ok to span 650mm cc i would say you may need a thicker decking to aviod any "spring" in the deck.

[seriph1]

decking guns can be hired I believe - that's how I did the last job for a mate. best to ask a tool place about nail guns I reckon..... as I am NO expert - auto parts compressors or bunnings ..... same type of product(GMC or similar), but easier to get replaced from bunnings when they break down......KEEP RECEIPT as they need it when replacing them, which they do without question. Try and get one model up from the base, is my motto.

[seriph1]

screws "can" be the way to go but take a huge amount more time to fix and if you twist the head off one, it is a big job to remove when it's the last one on that board. Nailing pre-drilled holes is the best solution I believe. What we did was set up 2 man teams - one person drilling, one nailing and making sure the boards were straight when the nails were inserted. and I was remembering incorrectly when I said we drilled and nailgun'd the ends - I recall now that we drilled and hand nailed the ends. I remembered because we used those nails as the spacers to keep the boards an even distance apart. Remember to do all you can to nail the boards in line, as it can look ugly if the nails are all over the place.

[ausdesign]

Greetings Corey.

I'd be checking out the decking span with the suppliers - 650 seems way too much spacing. In the new reg's there is also a difference between 'high' & 'low' decks in regards to spans.

My preference would be for 50mm gal nails [predrilled with a one eighth bit]in preference to screws. Screws have a tendancy to sheer off especially if drilling into seasoned hardwood joists, as yours will be if they've been down for a period of time. Plus depending upon the hardness of the decking in my experience, screws can tend to spin & not seat properly below the surface.

As an aside - It sounds as if your joists may be in good shape but normal hardwood joists [obhw f8] are not suitable for exposed use, although over the years they have been commonly used for decking joists. New reg's don't allow them. If your doing a large area with a fair bit of outlay i'd be looking at sealing the top of the joists with a bitumin paint or similar to protect the joists from rotting.

[seriph1]

Hi Pete - his deck "may" be undercover if it is the type of Queenslander we lived in as kids..... but all good points.

Corey - if the spans are too great there are a few non-drastic things you can do to remedy it. I am personally not fussed by the 650 even though it is over-distance for new places. I feel it would be most improbable that one could go through it once it is all on.

[conwood]

Hi Corey,
Irrespective of what you use, it's a good idea to cover bearers with plastic or similar before placing deck over them. Just that added protection from the elements.

If you can afford it, stainless screws are good, particularly if you may need access under at some stage. You can always unscrew and replace without bashing things.

Cheers,
conwood

[corey]

Thanks Steve

Yeah the deck is under cover as you suggested and the joists are very "Seasoned" as the house is about 100yrs old but they are in good shape. Not much I can do about the spacing but the old decking that is on it still manages to hold me up at 115kg so it should be ok. All points taken and much appreciated. The deck is only 2.4m * 8.5m so I may be doing a lot of pre drilling and hammering with a one eight bit and 50mm gal nails. Should I use twist nails?

[seriph1]

I never used twisties but it may be advisable - perhaps a tradie can advise. If you do want to reduce the span, you can marry-in members beside each joist, though as you say, it currently holds your waif like frame no problems.

:D

one further hint - get three new HIGH QUALITY 3mm drill bits...... will save downtime resulting in finding your car keys in the middle of it all

:D:D:D:D

[Trav]

I built a deck from recycled hardwood. The whole bang lot was drilled then hand nailed as its construction was spread over a few months.

I used 50x2.8mm hot dipped galvanised twist shank nails (what a mouthful). They wored a treat.

I would definitely stay away from screws:
1. more expensive
2. if the head shears off, it is a pain in the arris to remove - if you bend a nail, just rip it out
3. MOST IMPORTANTLY, screws will not at all fit the look of a queenslander. New deckign nails will look a bit out of place, but SS screws all over the deck will really look bad (IMHO). The heads of the screws are much bigger than the heads of nails and are much more noticeable.

I made up a jig (see picture attached) that enabled me to get all my nails in a neat line and gave me a guide as where to drill. I used 2.5mm (or maybe 2mm) drill bits (lots of them cos I broke them pretty regularly).

Have a look at http://www.woodworkforums.ubeaut.com.au/showthread.php?t=20204 to see how my deck wored out.

Trav

[seriph1]

Trav, were you intending to post a pic of the jig? I couldnt find it on the link

[Trav]

Trav, were you intending to post a pic of the jig? I couldnt find it on the link

Ooops, my bad. :o

Here is the jig I mentioned. :D

Trav

[Firewalker]

At the risk of going against the grain......I would use SS screws and fasten from below. The nails will eventually pop over the years without regard to insertion method. Sure the nail gun is faster but it is worth the time and added expense (to me) to have the holding power of screws.

The method of fastening from below will prevent having to look at any fasteners or having to try to line them up. There are fastening systems made for this application. If you do end up doing them from the top side I would snap a chalk line and put the screws (or nails if you insist) on the line. Will make for a nicer look in the end.

Best of luck.

Scott

I found a link for you to see what I am talking about. Would be worth it if you want it to look top notch!

http://www.westessexbuilding.com/deckmaster.htm

[sol381]

500mm is about maximum with 19mm boards. Would have to go to 25mm or 28mm thick to span that.. You used to be able ot use t-nails but most authorities recommend coil nails.. I use a 50mm dome head screw shank nail . they twist into the wood and seem to hold the wood firm against the joist. Screwing the joists probably will hold a bit better but wont look good and will take you 10 times as long.
stef

[julianx]

I prefer to stagger the nails as lining the nails up tends to increase the chance of the joists splitting.

[Ashore]

Go with the galvo nails , pre drilled , extra work but well worth it in the end.
You don't have to nail to each joist
The plastic over the joists is a great idea ( a lot of decking is grooved on one side and some people put this side up , but its designed to go down to allow air to flow between joists and deck to stop dry rot etc )
Newer flooring is toung and grooved on the ends so you don't need to join at the joists but in your case you have to butt up , so do it at the joist
So as to the but ends of the boards , if you take care and per drill (2 To each board ) at a slight angle you should have no trouble

The other alternative is to glue with very few nails / screws

As to twist nails , I have no idea , always gone straight , guess it was the way I was bought up.


The trouble with life is there's no background music.



Russell

[Geno]

Personally I prefer screws. I prefer the flush, sleek look and being able to easily pull a board up if need be. No concern about nails coming up ready for a little tacker to stub their toe on either. Neighbour went with the deformed shank nail ("Twistlock" or something) and they eventually work their way up.

Screws cost more and take longer though, and in some cases the look of the screws won't be what you are after.

Never had a problem with the heads shearing off and I did 600 linear metres of boards.

Like a lot of these things it is a subjective, with nails and screws each having their pros and cons.

[MrFixIt]

Hi

650 spacing is NOT a problem for decking spacing.

Use galvanised nails. You may be limited in what you can get as the nail "head" by the choice of nail hun you buy/hire.

With a width of 145mm I would not expect you to have ANY problem with splitting (except at the very end of course). So I do not see any need for predrilling, again except for the very ends. Allow the decking ends to cover half the width of the joists, a 45deg (vertical) mitre is good, but butt loints are just as good. Of course some of this is dependant on what appearnce the decking needs to have when finished.

Of course, in case you are not aware, stagger the joints on different joists. Lining them all up will weaken the structural ridgidity of the deck

Use two nails through the decking in each joist. Skew nail them, ie like this \ /, so that each nail helps prevent the other from pulling up. Use the nails with either a slight thread or "ribs" on them to help hold, though they may not be available for the nail gun. Check out what nails are available for any nail gun you may purchase.

Though I assume autostore compresors would work for a nail gun, as nail guns dont need a huge continuous CFM compresor output, I would not buy one of those autostore compresors as a first compressor. I think they would make a great little backup compressor.

When you buy a compressor, you'll find that you have other uses for it and therefore a good quality unit is best for your first compressor (IMHO).

[seriph1]

I think we used ring shank nails in our gun, the day we did the beck - 92 sq mtrs of it .... fun fun fun!
:D

[sol381]

650 spacing is NOT a problem for decking spacing.

Mr fixit , 650 is a problem and i assume you mean joist spacing. The maximum you should go is 500, 450mm is standard with 19mm boards. You`ll find the wider spacing you use the more bounce in the flooring you`ll get when you walk between joists. If this was getting inspected by a certifier it would have zero chance of passing. The widthe of the board at 145mm might help a bit but joist spacing is judged by thickness.
Seriph1, the ring shank nails are used for pins joists and twist are for hardwood. Ring shank hold really well but would have trouble nailing into hardwood.
stef

[Pulse]

I think type 17 50mm bugle head screw (batten screws) would look fantastic on 145 mm boards. They are used in commercial decking often at wharfs and jettys. They are driven in with 5mm internal hex driver bit. They look classy and will never shear.

Cheers
Pulse