Best way to seal duct and avoid a stream of water into the basement

[ragg987]

Hi, I have a small detail I would appreciate some input into.

 

We have an ASHP sitting on an external slab and 2 ducts going underground into our basement where they terminate. Electrics into one duct and refrigerant into the other. The services then go up from the basement into the plant room above (but not in the duct).

 

A slight oversight, at the time, now how would I seal these holes so as to prevent ingress of water or other stuff into basement? We have sprayed expanding foam on the basement side but the external (ASHP side)? Am concerned that foam may not be able to last many years outside?

 

 

[Bitpipe]

This is what you need. http://newtonwaterproofing.co.uk/solutions/seal-service-pipes/ They will sell it to you direct.

 

I used it in the basement to seal foul, water & electric services running through ducts that had been cast into the wall.

 

It basically never goes off and remains flexible.

 

I got a generic sausage gun from amazon, the Newton one was over £70.

[Bitpipe]

You may need to remove the first 150mm of the basement side foam to use this.

[ragg987]

Looks good. The video and guide shows it fitted on internal wall side, any reason I could not apply it to the outside (as per picture)? Trying to avoid opening the basement side as it is already boarded, plastered and painted.

 

I guess the disadvantage of this approach is that any leak in the duct would not get stopped.

[Bitpipe]

14 minutes ago, ragg987 said:

Looks good. The video and guide shows it fitted on internal wall side, any reason I could not apply it to the outside (as per picture)? Trying to avoid opening the basement side as it is already boarded, plastered and painted.

 

I guess the disadvantage of this approach is that any leak in the duct would not get stopped.

 

No idea - I assume that the ducts enter your basement horizontally?

 

The Stopaq is fairly viscous stuff (you have to pre-warm before using otherwise it refuses to come out of the tube) with the consistency of plasticine. If you follow their recommendation of stuffing the pipe with foam and then the remaining 150mm with the Stopaq and finally the mortar then you should have a pretty decent seal.

 

Looking at the ribbed duct, how is that waterproofed into the basement wall? I'd be more concerned about getting water between the outer duct wall and the basement wall rather than down the duct itself.

 

 

 

 

[ragg987]

Outside the duct is waterproof concrete and that is covered by a warranty, so I am pretty confident about that. Kryton system that contains some kind of crystalline material which will expand if water gets in and close any micro-cracks.

 

http://www.kryton.com/products/application/concrete-waterproofing-joints/

[Bitpipe]

We used Sika but same principle.

 

You should be fine then.

 

Make sure you calculate the volume you need to fill (i.e. diameter of duct less diameter of pipes times 150mm) and then figure how many tubes you'll need. They're about £25 each and the mortar is about £7 a tub. Tube is roughly 500g - I remember calculating the volume based on the density in the data sheet.

 

I posted a thread on ebuild about the applicator gun, ended up with this one from amazon -  - Everbuild Silicone Sausage Foil Pack Applicator Gun 15in - 600ml.

[Onoff]

Magic or Wiska Gel maybe?

[ragg987]

Spoke to Newton and they do not think this is the right application. I suspect this may be a warranty / liability thing as their solution seems to designed for use at the wall end.

 

I might try the potting options - Magic or Wiska. Seems widely available and is designed to work around plastics and electric cabling. Need to find a way to hold the liquid in the pipe before it sets - maybe push a bit of foam in there.

[Onoff]

8 minutes ago, ragg987 said:

Spoke to Newton and they do not think this is the right application. I suspect this may be a warranty / liability thing as their solution seems to designed for use at the wall end.

 

I might try the potting options - Magic or Wiska. Seems widely available and is designed to work around plastics and electric cabling. Need to find a way to hold the liquid in the pipe before it sets - maybe push a bit of foam in there.

 

Let's be honest you could squirt expanding foam in first. 

[Declan52]

Could you get a hold of some bentonite. Comes in pellet or powder form and is what we used around boreholes to seal up the gap around the pipe. Once it's absorbed the water and set it will be sealed for good.