Decking Gapping

[chirpychippy]

Hi,

I'm installing 27x144mm Canterbury Softwood decking on Monday, I might be overthinking this so please here me out.

The spacing recommended is 5mm, but the decking is stored outside at the timber merchants and as such has expanded to 147mm due the inclement weather.

Yesterday I cut and laid all of the boards ready for fitting, some were drier than others so I'm trying to get the moisture content more even.

Being that the decking has expanded by 3mm per board should I reduce the gapping to say 3 or 4mm, my concern is that when the boards dry out I could end up with large unsightly gapping??

Thank you

 

[mattylad]

How about dry them out before fitting?
That way they will be consistent.

 

[chirpychippy]

I'm not sure where I could dry 200 meters of decking, in the Autumn in the UK, mattylad?

Think I'll go with 3mm spacing, Thank you.

 

[big-all]

you could try alternating planks so a well swollen with less swollen at 3mm gaps but be prepared for gaps to settle at perhaps between say 4 and 10mm and iff you can accept that the go ahead if not you have to cover and air dry with sticks to allow air flow

 

[conny]

If this is for your own house, I would suggest waiting till the boards dry out otherwise you may have to start lifting and moving, (or even replacing), a lot of them.
If it's for a customer, then you have a potential problem if they complain in the future.

The lesson to be learnt from this is don't buy timber thats stored out in the rain I suppose.

 

[foxhole]

They can’t shrink enough to create unsightly gaps.

 

[^woody^]

If the nominal size is 144 and the gap to be 5mm, then you would lay the boards at 149mm edge to edge regardless of whether the board is wet or dry and they will then acclimatise to regular gaps.

 

[Lower]

Measure the spacing of each board to the next of the central rib, not the edge. The gaps will vary when first laid, but should even out as the boards equalise their moisture content.

 

[chirpychippy]

Measure the spacing of each board to the next of the central rib, not the edge. The gaps will vary when first laid, but should even out as the boards equalise their moisture content.

I think I understand what you are saying, these boards are reversible, rebated one side - flat on the other and it will be the flat side uppermost, so the central rib won't be visible in installation.

 

[chirpychippy]

If the nominal size is 144 and the gap to be 5mm, then you would lay the boards at 149mm edge to edge regardless of whether the board is wet or dry and they will then acclimatise to regular gaps.

Cheers Woody, yeh that took a while to sink in, or put it another way, 149mm centers regardless?

 

[chirpychippy]

you could try alternating planks so a well swollen with less swollen at 3mm gaps but be prepared for gaps to settle at perhaps between say 4 and 10mm and iff you can accept that the go ahead if not you have to cover and air dry with sticks to allow air flow

Air drying would be my preferred option, the customer is very exacting and this concerns me with the condition of this product, but I am against the wall, booked solid until beyond Christmas. I am going to lay it leave the screw heads just under the surface and await next year's heatwave and see what happens, hopefully the phone wont ring.

 

[big-all]

i make jigs for everything to make it quick and simple without the need to think or measure
my initial thought was front edge to front edge but would make it overly complicated even with purpose made jigs needing both pushing and pulling at the same time possibly a wedge to hold in position from the previous plank?? but adding to the complication
i then though a double plank and a gap jig so you hook over the last plank and new plank pushes tight away from the last one but this may cause uneven gaps
measuring centre to centre would be the closest but very time-consuming compared to spacing shims when dry

 

[chirpychippy]

i make jigs for everything to make it quick and simple without the need to think or measure
my initial thought was front edge to front edge but would make it overly complicated even with purpose made jigs needing both pushing and pulling at the same time possibly a wedge to hold in position from the previous plank?? but adding to the complication
i then though a double plank and a gap jig so you hook over the last plank and new plank pushes tight away from the last one but this may cause uneven gaps
measuring centre to centre would be the closest but very time-consuming compared to spacing shims when dry

I like a jig makes life simpler but as you say I can't think of one I can make for this scenario. Yesterday was bright sunshine and warm all day here in Kent on arriving at the job this morning the boards on measuring were mostly 145 - 146mm.
I have decided to work off of 294 overall, 2x144 + 5, yes it's 293 but 294 is fine, I'm measuring every board, it's going to ages, but ultimately it's my reputation and I'm also anal. Thank you for your help squire.

 

[foxhole]

I think I understand what you are saying, these boards are reversible, rebated one side - flat on the other and it will be the flat side uppermost, so the central rib won't be visible in installation.

They are not reversible, the flat side should not be used unless you want to break a leg.

 

[big-all]

my thoughts something like tile baton 38/50mm upwards
4/5" wire nail hole drilled [interference fit ] to make a jig and nails smooth so wont grip the wood and cause damage butting up and lifting out like a screw and narrow enough[around 3mm ]to not get in the way