Sealing floorboard edges against the weather. What potion?

[epsilonGreedy]

My brickie team will be restarting next week now that my first floor has been fitted and while the Caberdeck board edges are accessible I plan to brush on some type of sealant around the perimeter edge. I have a few litres of old solvent-based garage floor sealant kicking around and this soaked into my static caravan OSB skirting quite well. Alternatively I could continue and finish off the job using the same technique used by the pro carpenter who helped me fit the floor. He used up the remaining D4 glue on some edges, however when applied to the board edges this bubbles up higher than the board surface and helps retain a rainwater puddle on the surface, the depth of the D4 glue also reduces the mandatory gap between floor and wall masonry.

 

Should I consider something else, PVA for example?

Edited May 11, 2020 by epsilonGreedy

[PeterW]

Use the spare D4 glue.

 

There is no mandatory gap either - it is an expansion gap but TBH any expansion will crush the D4. The boards are 60 day water resistant through the core.

[joe90]

My Caberdeck floor was not sealed at the edges and stood in very wet conditions through winter with no degradation.

[wozza]

I used D4 adhesive, brushed on, yes it does give a slight lip as it bubbles, but any water soon evaporates off.

 

[Carrerahill]

44 minutes ago, epsilonGreedy said:

My brickie team will be restarting next week now that my first floor has been fitted and while the Caberdeck board edges are accessible I plan to brush on some type of sealant around the perimeter edge. I have a few liters of old solvent-based garage floor sealant kicking around and this soaked into my static caravan OSB skirting quite well. Alternatively I could continue and finish off the job using the same technique used by the pro carpenter who helped me fit the floor. He used up the remaining D4 glue on some edges, however when applied to the board edges this bubbles up higher than the board surface and helps retain a rainwater puddle on the surface, the depth of the D4 glue also reduces the mandatory gap between floor and wall masonry.

 

Should I consider something else, PVA for example?

I used some left over varnish and painted them all, had about 4 shades, tipped them all into one pot and used as a general sealer for many things during the build.

[Mr Punter]

I thought you had Egger Protect?  Anyway, if you are bothered, apply some PVA to the edges.

[epsilonGreedy]

39 minutes ago, wozza said:

I used D4 adhesive, brushed on, yes it does give a slight lip as it bubbles, but any water soon evaporates off.

 

 

I like the idea of brushing the D4 on. The messy bubbled up ends that the carpenter did at the end of the job were applied by dribbling the D4 out of the nozzle.

[epsilonGreedy]

4 minutes ago, Mr Punter said:

I thought you had Egger Protect?  Anyway, if you are bothered, apply some PVA to the edges.

 

 

So did I but when the 50 sheets arrived it was Norbord's Caberdek. The confusion was a prior quote direct from DWB a joist manufacturer included Egger but in the end I sourced the joists and decking separately. I tend to go with whatever my preferred BM stocks.

 

I have been impressed by the weather proof finish on the Caberdek and also the weight of each board.

[Mr Punter]

The weight is the same for the Egger.  I prefer the finish on the Egger as it is permanent instead of plastic covering.

[epsilonGreedy]

6 hours ago, joe90 said:

My Caberdeck floor was not sealed at the edges and stood in very wet conditions through winter with no degradation.

 

 

I am just being extra cautious about the possibility Covid might cause a disruption to roof slate supplies and hence an extra long period of exposure. After the physical exertions of last week including lifting 1 ton of floorboard sheets up 2m onto the scaffolding I am looking forward to an easy week and just painting on some sealant.

 

Edited May 11, 2020 by epsilonGreedy

[epsilonGreedy]

2 minutes ago, Mr Punter said:

The weight is the same for the Egger.  I prefer the finish on the Egger as it is permanent instead of plastic covering.

 

 

Yes I like the Egger finish (the one that seems to be a matt grey very thick paint finish)? My Caberdek has a permanent thin laminate finish which is a bit more prone to chipping when handled.

[epsilonGreedy]

1 hour ago, PeterW said:

Use the spare D4 glue.

 

There is no mandatory gap either - it is an expansion gap but TBH any expansion will crush the D4. The boards are 60 day water resistant through the core.

 

 

That's odd because the joist manufacturer's design and the carpenter assumed a standard 50mm gap around the floor perimeter. The 50mm gap looks unnecessarily large to my untrained eye but at the end of the day hybrid PIR/Plasterboard will bridge over this gap.

[joe90]

17 minutes ago, epsilonGreedy said:

standard 50mm gap

that seems  very large?  Mine was about 10mm especially after @PeterW figures on how little this stuff expands/contracts on a another thread. ( I don’t blame you for being cautious regarding sealing edges , I was ill and off site during that part of my build so missed it !).

[PeterW]

50mm is wrong - it’s 10mm 

 

Where has 50mm come from @epsilonGreedy..??

[nod]

1 hour ago, epsilonGreedy said:

My brickie team will be restarting next week now that my first floor has been fitted and while the Caberdeck board edges are accessible I plan to brush on some type of sealant around the perimeter edge. I have a few liters of old solvent-based garage floor sealant kicking around and this soaked into my static caravan OSB skirting quite well. Alternatively I could continue and finish off the job using the same technique used by the pro carpenter who helped me fit the floor. He used up the remaining D4 glue on some edges, however when applied to the board edges this bubbles up higher than the board surface and helps retain a rainwater puddle on the surface, the depth of the D4 glue also reduces the mandatory gap between floor and wall masonry.

 

Should I consider something else, PVA for example?

While the gap isn’t mandatory 

You do need to leave a minimum of 10-15 around the block work 

More than expansion its to stop the sound carrying from the floor to walls

Even your spec builders have someone go round with a chisel cleaning bricklaying snots out of the gap Prior to Pre plaster inspection 

[epsilonGreedy]

4 minutes ago, PeterW said:

50mm is wrong - it’s 10mm 

 

Where has 50mm come from @epsilonGreedy..??

 

 

10mm feels like a common sense expansion gap. Maybe I am confusing the joist to blockwall/chimney breast gap. I will go out to take some measurement and will report back.

[PeterW]

50mm between the joist and the chimney breast sounds a bit better but that is still a lot.

[joe90]

24 minutes ago, PeterW said:

50mm between the joist and the chimney breast sounds a bit better but that is still a lot.

especially as chimneys should be lined, mine was built using insulated liners and so still had a 10mm gap to boards.

[wozza]

50mm Wow - thats some expansion - if the floor / joists / glue expanded by that much it would surely tear itself apart?

 

Caberdek says this:

 

Perimeter expansion gap:

• It is important to leave an expansion gap of 2 mm per metre run of board between the edge of the floor and the perimeter wall or any solid abutment (minimum gap 10 mm).

• For larger areas it is necessary to incorporate intermediate expansion gaps to provide the necessary allowance for possible movements, particularly in corridor applications.

• Attention must be paid to maintaining expansion gaps at all times during construction.

Expansion and contraction provision:

• An expansion provision should be allowed of 2 mm per metre plus 1 mm for every metre above 12 m of the width or breadth of the area.

[epsilonGreedy]

2 hours ago, joe90 said:

especially as chimneys should be lined, mine was built using insulated liners and so still had a 10mm gap to boards.

 

 

My Architectural Technician favours insulated liner flue blocks but I went for standard pumice/cement flue liners. Now I am trying to work out how much vermiculite fill I will need, it is looking like 6 to 7 bags a chimney i.e. £120!

[epsilonGreedy]

3 hours ago, PeterW said:

50mm between the joist and the chimney breast sounds a bit better but that is still a lot.

 

 

Ok panic over, my floor board expansion gap varies between 10mm to 20mm, it was 50mm for the joist to chimney breast wall gap. Due to a timing problem the floor went in before the ground floor chimney blockwork so this can be tweaked to the floor aperture as it goes up.

 

According to the Caberdek technical doc the expansion risk in the decking is attributed to the newly installed floorboard sheets absorbing moisture.

[PeterW]

1 hour ago, epsilonGreedy said:

 

My Architectural Technician favours insulated liner flue blocks but I went for standard pumice/cement flue liners. Now I am trying to work out how much vermiculite fill I will need, it is looking like 6 to 7 bags a chimney i.e. £120!

 

How big are the liners / apertures..?

 

If they aren't built yet, you can always close off if you want width with block on flat but the vermiculite will be cheaper. Mixed 8:1 with cement and a sprinkle of water and loaded in as they go.

[epsilonGreedy]

22 hours ago, PeterW said:

How big are the liners / apertures..?

 

 

The flue liners are 235mm wide externally which gives 7" internally. We are trying to follow a local architectural style which requires an external chimney size 5 bricks wide and to simplify things this width will be taken straight down to the concrete flue base plate sitting on the internal cross lintels.

 

23 hours ago, PeterW said:

 

If they aren't built yet, you can always close off if you want width with block on flat but the vermiculite will be cheaper.

 

 

I knocked the first chimney breast down when the mortar was still green because it looked too big in the room. When the brickie returns he will rebuild this which should not be a problem because the internal wall has open sockets about 120mm wide to which the chimney best will be tied to.

 

23 hours ago, PeterW said:

Mixed 8:1 with cement and a sprinkle of water and loaded in as they go.

 

 

Aha. I imaged the vermiculite would have a quick spin in the electric mixer. Thanks for the tip.