ICF waterproofing

[deuce22]

Hi.

 

Has anybody here had to waterproof an ICF retaining wall?

 

Thanks.

[Conor]

We used a bitumen based self adhesive tanking membrane. Fairly standard, just need to protect it before backfilling.

[deuce22]

I've just started doing it on mine. I've painted a waterbased waterproofer/primer and then used a peel and stick membrane. On top of this goes the drainage board before filling with stone and then the earth backfill.

 

I've watched videos on this setup and quite a lot don't even prime the surface first. The reason I'm asking is because I assumed that it would be a lot more tacky when applying the peel and stick, but I don't know if i'm being to fussy. The last thing I want is to have to expose all this, once its backfilled because there's a leak.

 

I've got the rep for the company coming to check it, but I just wanted to get some feedback from what others found using this.

 

Thanks.

[markc]

Never done an ICF wall but loads of concrete, concrete needs a primer for stickiness!

I can’t see a problem going straight onto styrene, just make sure it’s clean and dust free.

[Happy Valley]

We had waterproof concrete in a 2800mm high ICF retaining wall. 

 

The wall was clad in blockwork and tanking slurry brushed onto it prior to back filling. 

[Haylingbilly]

2 hours ago, deuce22 said:

I've just started doing it on mine. I've painted a waterbased waterproofer/primer and then used a peel and stick membrane. On top of this goes the drainage board before filling with stone and then the earth backfill.

 

I've watched videos on this setup and quite a lot don't even prime the surface first. The reason I'm asking is because I assumed that it would be a lot more tacky when applying the peel and stick, but I don't know if i'm being to fussy. The last thing I want is to have to expose all this, once its backfilled because there's a leak.

 

I've got the rep for the company coming to check it, but I just wanted to get some feedback from what others found using this.

 

Thanks.

I had a Nudura wall done with Triton external tanking and as per your experience it was not very tacky at all.

 

[scottishjohn]

I suspect  installation temp will have a great influence on how tacky it is  if some sort of butyl based product.

 just like "flashband "  is 

[Conor]

2 minutes ago, scottishjohn said:

I suspect  installation temp will have a great influence on how tacky it is  if some sort of butyl based product.

 just like "flashband "  is 

Top tip from our supplier for working in cold weather.. Store the rolls in a warm house and install quickly before they cool down. Use a heat gun for corners.

[deuce22]

17 hours ago, markc said:

Never done an ICF wall but loads of concrete, concrete needs a primer for stickiness!

I can’t see a problem going straight onto styrene, just make sure it’s clean and dust free.

The primer is supposed to help with adhesion and also protect the EPS from the bitumen as it can eat into it.

 

14 hours ago, scottishjohn said:

I suspect  installation temp will have a great influence on how tacky it is  if some sort of butyl based product.

 just like "flashband "  is 

I believe this as well. I spoke with the rep and he said to heat the membrane with a heat gun in areas that are not as tacky.

 

14 hours ago, Conor said:

Top tip from our supplier for working in cold weather.. Store the rolls in a warm house and install quickly before they cool down. Use a heat gun for corners.

Thanks. They are stored inside, so I can't see what more I can do.

[deuce22]

15 hours ago, Andy brown said:

I had a Nudura wall done with Triton external tanking and as per your experience it was not very tacky at all.

 

I ended up using Wykamol as I found all other companies were overcomplicating things. Maybe its the same for all manufacturers then. How has it performed and how long has it been on?

I also have to do an internal drain system as they now require 2 forms of waterproofing. If anything does get through the external, the internal will collect it and drain it outside.

[BotusBuild]

i will be having waterproof concrete in Nudura wall, then for BCO and build warranty purposes will need the bitumen and "drainage board" system with a french drain at the base of the wall.

 

(All overkill according to the man supplying the Nudura)

[deuce22]

2 hours ago, BotusBuild said:

i will be having waterproof concrete in Nudura wall, then for BCO and build warranty purposes will need the bitumen and "drainage board" system with a french drain at the base of the wall.

 

(All overkill according to the man supplying the Nudura)

I'm assuming that you mean you are using Nudura ICF for the retaining wall and will be using waterproof concrete in this. If so, I wasn't allowed to do this as you cannot inspect the wall for the correct consolidation of the concrete once it's inside the ICF. It needs to be standard shuttering, where it gets removed after the concrete is set, so that it can be inspected and repaired if needs be.

I decided on A and C systems as I'd already purchased the Nudura for the retaining walls. I also think A and C systems is a more robust way, as anything that does come through will just get drained outside.

I't may be a bit overkill, but as I've been to other properties where they've had water coming through to the inside, it's a really expensive job to have to rectify it.

[BotusBuild]

Yes, just had a call with someone as it happens and it looks like I wil have to go A&C as well ?

 

[Haylingbilly]

6 hours ago, deuce22 said:

I ended up using Wykamol as I found all other companies were overcomplicating things. Maybe its the same for all manufacturers then. How has it performed and how long has it been on?

I also have to do an internal drain system as they now require 2 forms of waterproofing. If anything does get through the external, the internal will collect it and drain it outside.

So far so good, but don't want to tempt fate too much. Has been on for three years. It is a two story basement, and we have waterproof concrete in both stories, and internal tanking on lower level and external on higher level!

[deuce22]

20 hours ago, Andy brown said:

So far so good, but don't want to tempt fate too much. Has been on for three years. It is a two story basement, and we have waterproof concrete in both stories, and internal tanking on lower level and external on higher level!

Thanks.

 

I've got the rep coming net Wednesday, so I'll hopefully get it sorted.

[JOE187]

 Nudura used on my build  BCO would not allow nudura peel and stick as not BBA  approved at the time.

 I went for RIW  sheet seal 226 and protection board with out  primer. I only primed the  concrete footing. 

https://www.riw.co.uk/products/sheet-applied-systems/sheetseal-226

 

[Conor]

A bit more from me.

 

We went with just the self adhesive membrane under the slab and up the icf walls. Was told this would be enough. We have small amounts of water appearing at the corners of the slab. We're not fully rendered yet or have thresholds finished... But it's given me enough of a worry to not finish the basement now and instead put in a cavity drain system and drill a sump.

 

I would not rely on the membrane alone nor the concrete core and instead ensure you have two methods - i.e. a cavity drain and sump. 

[deuce22]

2 hours ago, JOE187 said:

 Nudura used on my build  BCO would not allow nudura peel and stick as not BBA  approved at the time.

 I went for RIW  sheet seal 226 and protection board with out  primer. I only primed the  concrete footing. 

https://www.riw.co.uk/products/sheet-applied-systems/sheetseal-226

 

That looks identical to what I'm using. I'm calling it peel and stick, but it's a cold applied bitumen membrane.  https://wykamol.com/products/sureproof-waterproofing-membrane

 

Did you put a 45° fillet at the bottom or just go straight down to the bottom of the wall?

[deuce22]

1 hour ago, Conor said:

A bit more from me.

 

We went with just the self adhesive membrane under the slab and up the icf walls. Was told this would be enough. We have small amounts of water appearing at the corners of the slab. We're not fully rendered yet or have thresholds finished... But it's given me enough of a worry to not finish the basement now and instead put in a cavity drain system and drill a sump.

 

I would not rely on the membrane alone nor the concrete core and instead ensure you have two methods - i.e. a cavity drain and sump. 

I had some damp coming through on the garage, but as soon as it was rendered it stopped. I don't really like the fact that there's no cavity, if there was a crack in the render it would more than likely track through to the inside. If I ever built this way again, I would definitely create a cavity with an outer leaf of block or brick.

[deuce22]

I'm just wondering if anyone has advice on drying out cement based products. On the area of cement fillet that hasn't been covered yet, the primer was completely washed off when it rained yesterday. Even though the surface was dry when I applied it and the primer was also dry, it was obviously still damp underneath. I've now put tarpaulins over the top of the walls to keep the wall, fillet and slab dry. However, there must be condensation building up as the walls are still getting damp and the moisture is running down onto the fillet/slab.

In an ideal situation, I would be doing this in warm, dry weather, but I have to try and get it done as it's holding me up. Using a heat gun is just going to dry the surface, so it won't really be a solution, I need to try and dry the whole thing.

 

Thanks.

[markc]

29 minutes ago, deuce22 said:

I'm just wondering if anyone has advice on drying out cement based products. On the area of cement fillet that hasn't been covered yet, the primer was completely washed off when it rained yesterday. Even though the surface was dry when I applied it and the primer was also dry, it was obviously still damp underneath. I've now put tarpaulins over the top of the walls to keep the wall, fillet and slab dry. However, there must be condensation building up as the walls are still getting damp and the moisture is running down onto the fillet/slab.

In an ideal situation, I would be doing this in warm, dry weather, but I have to try and get it done as it's holding me up. Using a heat gun is just going to dry the surface, so it won't really be a solution, I need to try and dry the whole thing.

 

Thanks.

Heat gun or blow torch (care needed not to pop the surface)

[JOE187]

Did you put a 45° fillet at the bottom or just go straight down to the bottom of the wall?

  Yes just used quick set cement  and primed when dry.

[Adam2]

Really interesting to read this thread as we have ICF (Nudura) with 200mm waterproof concrete. BASF products used around the slab, outside of below ground walls and in the concrete. probably about 6-7K of product. Fairly efficient to apply. As stated, temp for applying to ICF was an issue but use a heat gun and a big tank of propane and you get a 1st class adhesion.

 

A lot will depend on ground conditions - ours are very good - free draining sand.

 

We had BASF out to inspect each area and they were very helpful with guidance/training as needed.

 

As the wall junction with slab we used waterbar (on a raised concrete upstand in middle of the wall) and on the exterior before installing the membrane we used some leftover ICF cut into fillets to try and limit water build up at this weak area. also of course had land drain around the top edge of the slab on each floor.

 

It's rained a lot and no signs yet (fingers crossed!) of water ingress and we've had some decent rain. I guess our worst case scenario is a retrospective internal cavity which of course would be highly disruptive but at the moment this does seem unlikely.

 

Best of luck with whatever route you go and if you need BASF info feel free to message.

  

[Gus Potter]

56 minutes ago, Adam2 said:

Really interesting to read this thread

Yes it is. There is a lot of real practical info on BH.

 

If your just researching then the best thing to do to help yourself, save money and make in informed decision for your site is to learn as much about the ground as you can in laymans terms.

 

Try if you can to read a little about clay soils, gravels, rock and how ground water behaves. Next have a look at your site.. what is next door for example? Could your neighbours do something at a later date that may say raise or lower the water table? Your neighbours could also include the council / water board assets for example; roads, parks, sewers and so on.

 

Although hard to start you'll soon get a feel for the terminology of geotechnics and start to enjoy the fact that you are getting a handle on what can be a big cost risk. At first all you are trying to do is to learn enough so that you can ask the designers good questions. One of course is.. why are you doing it this way.. I'm paying you (designer) so can you explain why this is the best way to meet my requirements.. maybe you are just interested in the front end cost with say a 10 year guarentee or maybe you want more long term security / guard against water ingress say 20 -30 years down the line.

 

If say you are near the top of a hill on free draining gravel ground (see saveasteading on gravel soils called Esker) then the ground water is highly unlikely to develop any significant hydrostatic pressure.. here you are really talking low risk damp proofing.

 

At the other extreme.. jump now to say London and London clay which is pretty waterproof.. they use some of these type of clays to make dams out of. Here you could have other houses and say pavements close to your basement. Although the natural water table may be low you can experience times where water gets trapped against the basement walls. Significant water pressure can build up enough to damage your water proofing system.

 

Sounds scary but once you have read a bit and learnt how soils behave you'll start to get a feel for your site and confident to ask the right questions. Select the right water proof barriers and water proofing system. This will be easier as you have an overview of what you need for your job.

 

Lastly on a self build you are going to have to deal with the "builders". If you put this early work in then you'll get off on the right foot with the ground workers.. they will recognise that you "know a bit" and will be less likely to try and pull the wool over your eyes. They will then warn the brickie.. "Client knows a bit so don't muck about".. all the way up the chain!

 

 

 

 

 

 

Edited November 11, 2021 by Gus Potter

[saveasteading]

Can I ask why this needs waterproofing? Unless it is a basement or has a retaining wall element the only water should be dampness, not running water with any pressure.

For dampness, an inner liner might be ok, but it will be forced off with any sort of pressure from outside, in which case the liner should be outside.