Druidic Dabblings and General Twaddle !!

[Grahams]

On the mastic/sticky stuff front, we have been asked to quote for a job which this may be the solution. We have a concrete wall covered in 6x2 boards on 2x1 battens and a combination of poorly seasoned wood and general expansion/contraction due to heat/humidity etc has lead to gaps of 5 to 10mm between lots of the boards. The client wants these butted together with negligible gaps. My first thoughts were we can do that on the day, but given a change in the weather the boards will expand or contract again and the issue will reappear. If we used a flexible sealant instead that should cope with the movement. But on looking at the Sika website nothing jumped out at me. Any suggestions?
Graham

 

[doobin]

On the mastic/sticky stuff front, we have been asked to quote for a job which this may be the solution. We have a concrete wall covered in 6x2 boards on 2x1 battens and a combination of poorly seasoned wood and general expansion/contraction due to heat/humidity etc has lead to gaps of 5 to 10mm between lots of the boards. The client wants these butted together with negligible gaps. My first thoughts were we can do that on the day, but given a change in the weather the boards will expand or contract again and the issue will reappear. If we used a flexible sealant instead that should cope with the movement. But on looking at the Sika website nothing jumped out at me. Any suggestions?
Graham

What you want is what's termed a low modulus sealant. Nothing is going to stretch from 0-10mm, but given that the boards should now have seasoned and settled somewhat, any low modulus builders sealant should do the trick- it's a common construction demand. As you are outside it won't need to be neutral cure. I'd use No Nonsense from screwfix or similar, in a light brown to match.

If you think there's still a chance that the movement demands will be greater than normal, then go for a MS polymer sealant. They are a kind of 'do it all' sealant/adhesive and often have greater flexibility than silicon.

Call a specialist supplier and describe your problem. Each brand has different properties than the next, so they would be the best to ask.

 

[Shovelhands]

On the mastic/sticky stuff front, we have been asked to quote for a job which this may be the solution. We have a concrete wall covered in 6x2 boards on 2x1 battens and a combination of poorly seasoned wood and general expansion/contraction due to heat/humidity etc has lead to gaps of 5 to 10mm between lots of the boards. The client wants these butted together with negligible gaps. My first thoughts were we can do that on the day, but given a change in the weather the boards will expand or contract again and the issue will reappear. If we used a flexible sealant instead that should cope with the movement. But on looking at the Sika website nothing jumped out at me. Any suggestions?
Graham

Is there much of it? Could the boards be changed for tongue and grove ? They would possibly cope with the expansion and contraction and not show the wall behind. Or remove the existing boards and rebate them so they lap a little on each joint? You obviously need some extra boards to finish.

I think the biggest problem your going to have if you simply seal the joints, is getting a good bond to the wood, as it won’t be that easy to clean. I think I’d want to do it when it’s dry and the gaps are biggest, so when the boards swell it compresses the sealant rather than doing it when the gaps are tighter and then needing the sealant to cope with the contraction and needing to stretch, thus relying on the bond to the wood.

I have some Sika in stock that I used for wall joints, it’s brown, I will see what the code for it is.
I also like the Mapesil stuff out of Screwix, and they also do Sika EBT with seems quite good.

 

[fred]

On the mastic/sticky stuff front, we have been asked to quote for a job which this may be the solution. We have a concrete wall covered in 6x2 boards on 2x1 battens and a combination of poorly seasoned wood and general expansion/contraction due to heat/humidity etc has lead to gaps of 5 to 10mm between lots of the boards. The client wants these butted together with negligible gaps. My first thoughts were we can do that on the day, but given a change in the weather the boards will expand or contract again and the issue will reappear. If we used a flexible sealant instead that should cope with the movement. But on looking at the Sika website nothing jumped out at me. Any suggestions?
Graham

not sure mastic would look that great.

I'd be inclined to overboard the gaps with 4 x 1 and make then uniform so it looks a proper job. Dare say cheaper and quicker.

 

[Grahams]

Thanks for the replies.
Each wall is about 25x20m.
We had suggested over boarding the gaps, but they wanted a smooth finish, so we suggested overboarding in 8x4 sheets of marine ply, but they didn’t like that either.
I have seen it covered in 500x500x50mm rubber tiles, but they cost is huge and the tiles have popped off before due to heat expansion. A tile of that size falling 20m is going to hurt.
Basically the design came out, I would guess in the 80’s and they have lived with it until now, but a new safety person has said it is an issue and needs fixing, but are not willing to approve a design change, so we are a bit stuck. We can just go along with reboarding, but a lot of the wood won’t be reusable so with new wood there will be the same issues down the road which we are trying to overcome.
Graham

 

[diggerjones]

Yes i would over board like hit and miss fencing. Or start again with featheredge boarding

 

[Grahams]

Or remove the existing boards and rebate them so they lap a little on each joint? You obviously need some extra boards to finish.

That seems like it may be the best idea, if they are willing to accept a bit of compromise. The spec is a minimum of 50mm wood covering the wall and if they pulled apart there would be places were it would be 25mm, but as it is currently zero this may be the way ahead.
Graham

 

[Grahams]

Sorry Graham, sidetracked your thread. I think we have basically talked it out, but if it looks like running on I’ll start a new thread.
Graham

 

[V8Druid]

Sorry Graham, sidetracked your thread. I think we have basically talked it out, but if it looks like running on I’ll start a new thread.
Graham

no worries Gra ....... dare say I've done it to yours somewhere in the past .... 50mm of wood is a lot of covering ..... 3 layers of 18mm ply, all half lapping each time'd cure any gaps for sure

 

[V8Druid]

Like a cripple this morning ..... too much time on my knees yesterday persuading the cables into their new home in the floor, making connections, sealing and securing everything ....

this channel contains our oil line from the tank (now in't black shed and the boiler in the house ....

would've been happier to see it a few inches deeper, but I wasn't gonna disturb the oil line and it's only two to three inches wide so doesn't suffer much in the way of loading

the 'python' and a.n.other conduit, for lighting control, took some wrestling into place ..

especially at the house end ....

was pretty rough here yesterday and we were getting rained on by this point, so it got strung out/coiled up out the way (that barge board's looking a tad ropey)

Was gonna run them both along the bottom of the wall in a similar gulley, to the oil pipe's one, between the wall and the flag stones, then up the wall in the corner ..... but ..... couldn't get the buggers between the drain gulley and the wall ...some one'd gobbed a load of mortar in the gap ......so a rethink is being had

did manage to get the shed end trimmed, glanded up and terminated, ready for its box, before the light beat me

Today has been seriously wild here .... horizontal rain and howling winds .... can't put anything down unless it's bloody heavy
got the box onto the shed end .....

a feed up to the consumer unit laid in ready, for when it arrives ....

I love Anaconda .... much easier to wrestle than pythons ...... everything got terminated .....

and 'buttoned down' for the night

any suggestions for capping that duct off? ..... but'd need to be able to open it again if need be .. in case ---- expanding styro foam???
the second gland and duct is to allow a.n.other cable up the patch to provide a new leccy feed to me boxes, as and when they get relocated ... soon hopefully

on a side note for @Regy53 ..... thoroughly impressed with the system's ability to remember what I've written .... bloody power has been off four times this evening - twice whilst trying to compose/post this ... ..... re-booted and came back here - hey presto - the system has it all, word for word
IMPRESSED

 

[pettsy]

any suggestions for capping that duct off? ..... but'd need to be able to open it again if need be .. in case ---- expanding styro foam???

4” soil pipe cap with a bit of silicon sealant?

 

[Stock]

Use steel wool to plug the duct, the long tailed feckers can't handle it................................

Young las played a quarter final in this today and won............................

 

[V8Druid]

Use steel wool to plug the duct, the long tailed feckers can't handle it................................

Young las played a quarter final in this today and won............................

looks like you had the same sort of rain as we had ....... 'cept yours was frozen
I like the steel wool idea

 

[Powerfab]

On the mastic/sticky stuff front, we have been asked to quote for a job which this may be the solution. We have a concrete wall covered in 6x2 boards on 2x1 battens and a combination of poorly seasoned wood and general expansion/contraction due to heat/humidity etc has lead to gaps of 5 to 10mm between lots of the boards. The client wants these butted together with negligible gaps. My first thoughts were we can do that on the day, but given a change in the weather the boards will expand or contract again and the issue will reappear. If we used a flexible sealant instead that should cope with the movement. But on looking at the Sika website nothing jumped out at me. Any suggestions?
Graham

Grah,
Just checking, is this an external free-standing wall?
Combustibility and spread of flame has to be a consideration if its on a building in any shape or form.

 

[Powerfab]

Gra,

Fill the duct end with steel wool as mentioned, cap off with one of these https://www.amazon.co.uk/dp/B00AO76BYS/ref=dp_cerb_2
You can get them in various diameters to match your duct diameter. Gives you a pre-cut for the cable and the option of adapting if other cables have to be run later on.

 

[V8Druid]

Gra,

Fill the duct end with steel wool as mentioned, cap off with one of these https://www.amazon.co.uk/dp/B00AO76BYS/ref=dp_cerb_2
You can get them in various diameters to match your duct diameter. Gives you a pre-cut for the cable and the option of adapting if other cables have to be run later on.

great idea Boyo
this is 60mm ducting so I'll have to measure the internal tomorrow .... plastic tube end caps also spring to mind now too
a good dose of wire wool behind 'em too for Ratus Ratus ..... in case ..... no chance of anything getting in t'other end in the wall ... the box is covering it ...... and sod all came out when the snake went down it

 

[V8Druid]

Thanks for the replies.
Each wall is about 25x20m.
We had suggested over boarding the gaps, but they wanted a smooth finish, so we suggested overboarding in 8x4 sheets of marine ply, but they didn’t like that either.
I have seen it covered in 500x500x50mm rubber tiles, but they cost is huge and the tiles have popped off before due to heat expansion. A tile of that size falling 20m is going to hurt.
Basically the design came out, I would guess in the 80’s and they have lived with it until now, but a new safety person has said it is an issue and needs fixing, but are not willing to approve a design change, so we are a bit stuck. We can just go along with reboarding, but a lot of the wood won’t be reusable so with new wood there will be the same issues down the road which we are trying to overcome.
Graham

how about that recycled plastic boarding ..... no idea what it's called, but IIRC it's cheaper than Marine ply .. by a lot ......... 's hell of a wall .. 10 sheets long and 16 high .... t
hat is some sort of sail, in a high wind ..... wouldn't be stood up here tonight, after the gales we've had today / this evening .... probably be in Herefordshire , heading South West

 

[Monkeybusiness]

how about that recycled plastic boarding ..... no idea what it's called, but IIRC it's cheaper than Marine ply .. by a lot ......... 's hell of a wall .. 10 sheets long and 16 high .... t
hat is some sort of sail, in a high wind ..... wouldn't be stood up here tonight, after the gales we've had today / this evening .... probably be in Herefordshire , heading South West

Stokboard? It’s great stuff but expands/contracts a fair bit with temperature fluctuations.

 

[Shovelhands]

This ‘wall’.....is it at a firing range? Or some sort of blast wall?

This may explain the spec for 50mm of timber, and also explain why ply may not be suitable, as it may be more prone to ricochet of projectiles, this would definitely rule out any sort of plastic planking or boarding I would assume.

 

[Grahams]

This ‘wall’.....is it at a firing range? Or some sort of blast wall?

This may explain the spec for 50mm of timber, and also explain why ply may not be suitable, as it may be more prone to ricochet of projectiles, this would definitely rule out any sort of plastic planking or boarding I would assume.

Yes it is on a firing range, hence they are quite fussy about fit and materials. Any new material has to be approved for safety before use. I think the best option is to router out an overlap on each board so there is always a minimum of 25mm cover even if the joints open up. Wood won’t stop direct shot, but is very effective at stopping ricochets and fragments. I guess to do with the density and fibrous nature, so if a bullet passes through and bounces back off the concrete it will get caught in the wood rather than come back and hit someone.
Going on how thick the concrete is I don’t think it will blow away any time soon.
Graham