Roof Penetrations Leaking

[Jethro Bush]

Hi, I own a contracting company in N.Z. and a major problem we have is stopping leaks from pipework penetrations if we mount a condensing unit or solar panels on a roof. Any ideas of products that can help solve this prob?

[Magoo]

Hi Jethro.
Dectites and sealant from wholesaler or hardware store, they also come as split variety so can be fitted after pipe installation.
magoo

[Jethro Bush]

Hi Magoo, yeah, we seal them up and use Dektites and even use Denso grease tape but eventually they leak. Pain in the neck.

[rude]

decktites and silcon... could even use a tar based brush on paint to add a sealant coat, that usually does the trick.

[Brian_UK]

Are you using a properly constructed upstand on the roof for your pipes etc or just making a hole and routing stuff through that?

edit: Sorry, forgot to ask - are these flat or pitched roofs?

[Jethro Bush]

Pithced or flat. Same problem in both cases. Do you guys have an off the shelf kit available in U.K.?

[Brian_UK]

OK, how do you construct your penetrations?

[Jethro Bush]

A short length of 65mm pvc pipe, 90deg bend + 90deg bend. A Dektite boot flashing seals the roof to the pipe with a bit of sealant. The rough guys just bring the pipes up through a hole, boot flashing, sealant and grease impregnated tape

[Jethro Bush]

What do you guys use?

[lowcool]

roof and gutter,whatever as long as its not water based

[Jethro Bush]

Do you take your pipes through an upstand or just go up through a hole in the roof?

[lowcool]

cut a hole,apply silicone to dektite base liberally,screw it down,flatten raised portions,remove and smooth off excess and seal screw heads with it ,apply silicone to inner of dektite were it contacts pipe,build up surface and smooth off,only time i ever had leaks is when a sparks has been at it.

remember an electrician is a fridgie with half his brain removed

[lowcool]

if you are using pvc pipe upstand,screw and silicone a floor flange to roof then glue and silcone pipe through floor flange,cheap and effective.

[Jethro Bush]

I'm waiting to hear from Brian in the U.K. to see how they do it. Any USA or S.A. comments would be appreciated too.

[Monka]

Hi. 1st day on the forum site. Our guys have used a system they get from one of the wholesalers thay say is the bees knees. I'll see if any of them have a photo of an install and post it later.

[lowcool]

he might be sleeping

[Brian_UK]

he might be sleeping

Might have been

I suppose it depends on the type of roof construction.

I prefer to see a built upstand with the roofing material brought up and into the opening. This provides a weather seal for the roof itself.

Services can then be run into the upstand and suitable lids/covers made up to seal the top of the upstand as well as a peaked cap arrangement to cover the service entry.

[Monka]

Found a few photos and have put them together. The bottom right hand picture is based on the way our guys have been doing them

[fridgemandan]

mix your own fibre glass ive used it for years, pretty good, just paint over with roof sealant after cured

[ozairman]

Hey Jethro, have you ever looked closely and seen exactly where the water is leaking from? Sorry if it sounds dumb but it is not tracking along/inside pipe insulation or anything like that?
Slightly off topic I once found a water leak on a cassette unit drain connection where the drain pump water had pushed through the silicone the installer used to fill the gaps instead of using the correct sized pipe for the connection.