Can you recommend an external waterproof sealant

[AVI_8]

Can anyone recommend a sealant for external use on a wooden structure? Workshop is a log cabin style building, water is getting in at the 90 degree supports where there is no rebate in the timber, this happens when there is a strong wind.
Last night it was 60 mph wind with biblical rain and this morning I mopped up 4 buckets of water.
Silicone sealant helps for a while but I think it’s the UV rays which breaks it down, I tried Ever Build window sealant, what a pile of crap that is, the rain just washes it away leaving brown stains.
The timbers were properly seated when I built the workshop and it’s been treated with a high quality product so that’s not where the issue lies.

 

[hotponyshoes]

Sikaflex and the like is probably the best stuff for that.
I use it to seal up horseboxes and it seems to last pretty well.

I've got a load of out-of-date tubes of white if you want some cheap to try out?

 

[AVI_8]

Sikaflex and the like is probably the best stuff for that.
I use it to seal up horseboxes and it seems to last pretty well.

I've got a load of out-of-date tubes of white if you want some cheap to try out?

Thanks that’s very kind of you but i’ll need brown or it would be very noticeable

 

[mike os]

Sikaflex ... the preparation is the most important thing, surfaces must be clean and dry

 

[AVI_8]

Would this be the correct one?

Sika Sikaflex EBT+ All-Weather Sealant Brown 300ml - Screwfix

Order online at Screwfix.com. High strength construction adhesive. Fast curing time with powerful intial grab. Multipurpose and permanently elastic. Also suitable for joint sealing and filling. FREE next day delivery available, free collection in 1 minute.

www.screwfix.com

 

[mike os]

Would this be the correct one?

Sika Sikaflex EBT+ All-Weather Sealant Brown 300ml - Screwfix

Order online at Screwfix.com. High strength construction adhesive. Fast curing time with powerful intial grab. Multipurpose and permanently elastic. Also suitable for joint sealing and filling. FREE next day delivery available, free collection in 1 minute.

www.screwfix.com

As good a choice as any

 

[hotponyshoes]

521 would be ideal if it's under constant uv exposure but I'd think the ebt would be fine.

 

[8ob]

The problem with timber is the summer/winter wet/dry expansion and shrink rate, something non setting might be the answer. Got some black gutter sealer for a similar problem, its bitumen based and that doesn't set.

https://www.zoro.co.uk/shop/adhesives-and-sealants/silicone-and-caulk-sealants/c3-roof-and-gutter-sealant-310ml/p/ZT1014645X?utm_source=google&utm_campaign=pla+|+Adhesives & Sealants&utm_term=ZT1014645X&utm_medium=pla_css_3&targetid=aud-640926587892la-397909958052&loc_physical_ms=9045834&dev=c&gclid=EAIaIQobChMIgfuppsLJ_AIVAp7tCh0J_gFBEAQYASABEgIW5fD_BwE

Bob

 

[hotponyshoes]

The problem with timber is the summer/winter wet/dry expansion and shrink rate, something non setting might be the answer. Got some black gutter sealer for a similar problem, its bitumen based and that doesn't set.

https://www.zoro.co.uk/shop/adhesives-and-sealants/silicone-and-caulk-sealants/c3-roof-and-gutter-sealant-310ml/p/ZT1014645X?utm_source=google&utm_campaign=pla+|+Adhesives & Sealants&utm_term=ZT1014645X&utm_medium=pla_css_3&targetid=aud-640926587892la-397909958052&loc_physical_ms=9045834&dev=c&gclid=EAIaIQobChMIgfuppsLJ_AIVAp7tCh0J_gFBEAQYASABEgIW5fD_BwE

Bob

Sikaflex seems to stretch pretty well.
I've taken horseboxes apart where the boards are so rotted all the screws/fixings have pulled out and the panels have moved 1/4"+ and the sika is still holding on in there...

 

[bert]

Don't they use sika to seal caravans and they wobble about a lot.

 

[gaz1]

Can anyone recommend a sealant for external use on a wooden structure? Workshop is a log cabin style building, water is getting in at the 90 degree supports where there is no rebate in the timber, this happens when there is a strong wind.
Last night it was 60 mph wind with biblical rain and this morning I mopped up 4 buckets of water.
Silicone sealant helps for a while but I think it’s the UV rays which breaks it down, I tried Ever Build window sealant, what a pile of crap that is, the rain just washes it away leaving brown stains.
The timbers were properly seated when I built the workshop and it’s been treated with a high quality product so that’s not where the issue lies.

first off can you point to what type of log cabin build did you use

sealing it may solve one problem but will cause other problems

 

[AVI_8]

first off can you point to what type of log cabin build did you use

sealing it may solve one problem but will cause other problems

Supposedly Scandinavian pine, manufactured and shipped from Lithuania, bought from a company in England called Quick Garden.
The water is coming in at the 90 degree supports there’s 2 on each side wall and 4 on the front and rear walls. The logs are 70mm thick

 

[Trevorleach]

I have used the PU sealant from toolstation for all sorts, from sealing shower tray corners/sealing boat water intakes for cooling water/glueing skirting boards/upstands etc

 

[gaz1]

Supposedly Scandinavian pine, manufactured and shipped from Lithuania, bought from a company in England called Quick Garden.
The water is coming in at the 90 degree supports there’s 2 on each side wall and 4 on the front and rear walls. The logs are 70mm thick

if at the 90s uprights my advice would be to fit external woods or plastics to create a pillar which has air moving inside of them

this will make this area more water proof that what you have already as it shifts the issue onto the flat pieces which are sealed

 

[winchman]

I once call Sika the maker of Sika flex really helpful they have something for every application, it wasn't the cheapest and needed an applicator cleaner but it did the job to perfection

 

[AVI_8]

if at the 90s uprights my advice would be to fit external woods or plastics to create a pillar which has air moving inside of them

this will make this area more water proof that what you have already as it shifts the issue onto the flat pieces which are sealed

That’s something I was considering, as @8ob mentioned, this building moves with expansion and contraction over the seasons.
I’ll try the Sikoflex and if that doesn’t work I can make up some wooden structures in a U shape to go round the supports fixed with one attachment and the rest in a slot as that’s necessary with this type of building, I can see by the markings on the storm braces that the height of the building varies by more than an inch from summer to winter believe it or not, if done in wood and stained the same colour it’ll blend in with the building.

Thanks for all of your comments guys.

 

[gaz1]

you would be wasting your money

ive been considering whats best as i dont know how far those legs stick out

I was considering using decking and router the center of it out so a rubber seal can be fitted down its edge you need it both sides though and one piece over the front

as the decking has slots in it already then it can give a little air movement but the edge would need routing or trimming with a tablesaw or circular saw this is for drying out purposes

or its use plastic which will fade but wont want staining

 

[addjunkie]

I used leadmate on a joint in my shed in the end after trying various other selants. Been ok a few years since

 

[DaveB]

Water will either be blown through the joins if they are open or sucked throught by capillary action if the joins are tight.

I don't think you'll have much luck applying any kind of joint sealer in the winter when the timber is wet and has expanded.

Wait for the summer to dry things out and cause the gaps to open then apply a coating to the timber that rejects the water, if the gaps between the timbers have opened the coating can be worked into the gaps.

 

[AVI_8]

Yes I think capillary action is part of the problem, there’s three coats of Sikkens wood preservative on the building and I was very particular on the end grain of the supports

ive been considering whats best as i dont know how far those legs stick out

About 3 inches Gaz