Joins in decking?

[Tubby2]

I've just finished two smaller decks and I've been lucky to be able to build them without having a join in the decking.
I'm about to start on a larger one and I wont be that lucky with this one.
I'm trying to get a few hints and tips on joining the decking.
I've got a 90x45 joist at 500 centres and am using 90x19 Merbau. I'm fixing the decking with 10g 50mm stainless square drive screws.

I saw a picture in another thread that there is 2 joist to support the join below
http://www.woodworkforums.ubeaut.com.au/attachment.php?attachmentid=59078

But there didnt seem to be any extra joist in another picture I found
http://www.woodworkforums.ubeaut.com.au/attachment.php?attachmentid=59378

I'd also like to know which way is correct to fix decking or is it just personal choice as in the thumbnail below.
Is there a trick to getting the joints lined up flush or is it just experience to get it looking good.
I assume the first thing would be to make sure both ends are square but after that I have nothin.

Cheers

[SilentButDeadly]

Both are correct but the former uses more materials....

Board fixing layout comes down to personal preference....

Tricks? Avoid joins!! But after that the main one is to cut square. The only other thing that I remember from the last one was using a couple of small brad nails....hammer half way into the end grain of the fixed down side of the join, chop the head off with wire cutters and push the new board onto them - useful way to hold ends in place where the board was a bit kinked

[DJ’s Timber]

Another one is to stagger the joins over the whole deck so that they aren't as noticeable then

[Tubby2]

Beauty:2tsup: Thanks guys.

So if I just stick with the single 45mm wide joist, theoretically each decking end bit should have 22.5mm sitting on the joist. I'll give that a crack this arvo and see how I go.

Cheers
Guys

[oohsam]

Hey tubby, thats my pic!
I double joisted the joins becuase I was advised that the screw should be 20mm in from the edge. with a 45mm joist, that would leave 2.5mm each side for the screw to hit...
That was not enough for me to gamble with, and I was finding boards were splitting anyway... Bringing the screws in 5mm also was a risk as I split a few ends of the boards, even with predrilling, then I had to cut the board and I lost 450mm of merbau...

I had some spare joists lying around, so I double joisted the joins.
I had 2 joins the whole span of the deck, with 3 different lengths, so 6 extra joists dropped into place where there were joins. Pretty easy stuff actually.

The only thing to remember is to ensure the joists are the same level, u may have to pack or shave a bit of joist to get them level on the join if you double joist.

Like i said, with me it wasnt the 22.5 mm sitting on the joist, it was the 2.5mm for the screw to hit...

Merbau is too expensive to lose 450mm every time u split a board!

Cheers

[brynk]

gday tubby II

the second piccy was from my recent effort - for the joins over one joist i should elaborate - i drilled a pilot hole (2mm) back into the joist at an angle of about 60 degrees, from about 5mm in from the edges of the joist.

i then drilled a second hole of a larger diameter (3/32") into the decking board because if you try to force the nail through the initial pilot it will split the decking board. if you're using hardwood joists dip the gal nail (2.8mm x 50 gal bullet heads) into your decking oil and drive it through. maybe a piccy will help

although somewhat labour intensive, once you get a roll-on it goes relatively smoothly. make up a steel plate-jig with pilot holes to guide your drilling - this will protect your deck from drill damage - the method has proven to be successful up until now. we've had no lifting of boards or split 'enz' as the joists have shrunk and the decking has settled, and we have had some good rain over the last couple of weeks. here's hopin; or dare i say it, touch wood ;)

r's brynk

[Tubby2]

Thanks again for the feedback guys,
I fixed a few boards down last night and although I'm not extremely happy with the joins, it seems the screws are holding tight and no split boards.......yet!
The drop saw I am using had a 24 tooth blade on it so I;m blaming that for the not so perfect joins. I went to bunnings and bought another blade with something like 50 odd teeth so it should give me a finner cut and a better join, or thats the theory anyway.

Thanks again.

I'll post up some pics of the progress

[Loki429]

One quick tip when cutting the ends of your boards - set your saw on a bit of an angle (1 or 2 degrees) so that you undercut them. This way when they join together the top sides will butt together nicely.

The 50 tooth saw blade should be good too. I'm using a 60 tooth and getting nice clean cuts.

[UteMad]

I use a blunt electric knife it works a treat!!!!!! Only kidding ... Just put a tiny packer on the base of the drop saw under the board to cut a frack more out of the bottom side of the board and guaranttee the tops touch... Also try and make sure the board touch's both fences on the drop saw ... either side of the blade to make sure the board is square to the saw.. If you do this joints will be perfect unless your saw has been knocked out .. If this is the case tip it over and adjust the limit screws to make it square....

Also set your first board and every fifth up with a string line to make sure the run is straight.. If you have a curve in the run of the board it will make the joins messy


Anyway i am off to fraser island tomorrow cause i see decks in my bl**dy sleeep ..... Enjoy building yours and i will enjoy the sunsets and beach ....

cheers utemad