Has anyone incorporated concealed gutters into pitched roofs?

[SteamyTea]

I like the look, or lack of look, of concealed gutters and downpipes.

Trouble is, it needs an almost complete redesign of a roofing and wall system, that can cope when the guttering fails.

This basically means that two sets of guttering are needed.

Then some form of insulation is needed to minimise any condensation risks.

And that is just the guttering.  Down pipes are even trickier if they have to connect, in the right place, to the main guttering, and also pass though the secondary 'safety' guttering, while keeping any joints water tight.

Then, you have to deal with any joints in the downpipe that, once the cladding is in place, cannot be seen if they fail.

And all this has to be made in a material that will not fail for 60+ years, and must be repairable if it does.

And it must be fitted by some 'lads' on site.

 

Seems an ideal job for GRP.

 

 

[BartW]

1 hour ago, SteamyTea said:

I like the look, or lack of look, of concealed gutters and downpipes.

Trouble is, it needs an almost complete redesign of a roofing and wall system, that can cope when the guttering fails.

This basically means that two sets of guttering are needed.

Then some form of insulation is needed to minimise any condensation risks.

And that is just the guttering.  Down pipes are even trickier if they have to connect, in the right place, to the main guttering, and also pass though the secondary 'safety' guttering, while keeping any joints water tight.

Then, you have to deal with any joints in the downpipe that, once the cladding is in place, cannot be seen if they fail.

And all this has to be made in a material that will not fail for 60+ years, and must be repairable if it does.

And it must be fitted by some 'lads' on site.

 

Seems an ideal job for GRP.

 

 

Yes, GRP was the way to go with this, but as you say it is a complete roof redesign. I have sat on it for a few weeks now, and general conclusion is that everyone apart from the looks speaks for something more conventional. So, the question is what to swap it for?

 

I was going to have a clean transition between the pitched roof side and the wall. I am now thinking of adding a section of pressed aluminium gutter along the side that would hopefully disappear if done in matching black powder coat (on black slate tiles).

 

 

 

 

[SteamyTea]

@BartW

Have you thought of creating your own design, total from scratch, without using any pre-existing components.

This may sound an odd thing to do, but sometimes it is the only way.

Then get the components made.

 

For a one off design, it is really down to folding sheet metal, or moulding GRP.

Sheet metal folding does not require any tooling, just machinery, GRP does require tooling, though this may just be Contiboard and car filler.

The biggest problem, which is true for all building, is the actual fitting. Let's face it, plumbers an electricians use bog standard parts, made to a high quality, and still make a pigs ear of it, constantly.  This is part of the reason I think starting with no existing components may be a better idea.  You are just solving two problems; the functionality and the fitting.

[Dave Jones]

just to add, we previously lived in a G2 with a valley gutter along the end of the roof behind a parapet. Was zinc, lead and tin previously. we ripped it all out and made a trough from OSB then had a firm lay rubber the whole length at 1.5m up the roof as well just in case of moss blockages etc.

 

never dripped after.

[BartW]

52 minutes ago, SteamyTea said:

@BartW

Have you thought of creating your own design, total from scratch, without using any pre-existing components.

This may sound an odd thing to do, but sometimes it is the only way.

Then get the components made.

 

For a one off design, it is really down to folding sheet metal, or moulding GRP.

Sheet metal folding does not require any tooling, just machinery, GRP does require tooling, though this may just be Contiboard and car filler.

The biggest problem, which is true for all building, is the actual fitting. Let's face it, plumbers an electricians use bog standard parts, made to a high quality, and still make a pigs ear of it, constantly.  This is part of the reason I think starting with no existing components may be a better idea.  You are just solving two problems; the functionality and the fitting.

 

Hey, yes that was my approach, but it calls for some compromise. I am basically slightly uneasy about running the downpipe internally through the house. And quite frankly this is the only thing preventing me from just going with it.

 

My 5th post from top here explains what I was getting at: 

 

 

 

 

 

[Temp]

 

2 hours ago, BartW said:

I am basically slightly uneasy about running the downpipe internally through the house

 

One option might be to notch the outside of the house and recess the down pipe into that. I'm thinking a notch mostly filled with a square down pipe. Might mean a pier on the inside but perhaps those are needed somewhere anyway? 

 

Edit: Google images found this but I don't like the bottom...

 

 

 

   

 

or on full show..

 

 

[BartW]

Yeah,

 

the notching was being considered, but that would mean I need to notch the structural part of the building, which I am rather not keen on. I get two layers of battens @ 25mm thick, behind the slate tile rain screen cladding, so in theory that's just another 20ish mm to notch, BUT.... is this asking for trouble somewhere down the line?

[bob the builder 2]

HI

 

I would be really interested to see how MCB designed in the hidden gutter

 

@Bartw or laurenco - if you had time to share i would really appreciate it 

 

thanks 

[BartW]

On 28/10/2021 at 22:43, bob the builder 2 said:

HI

 

I would be really interested to see how MCB designed in the hidden gutter

 

@Bartw or laurenco - if you had time to share i would really appreciate it 

 

thanks 

 

Hi,

My build is going ahead with English Brothers. They were not very keen on designing any of the detail, so I did it myself.

 

I am using the benefit of a timber clad construction. The particular facade with the gutter in question will be built on 50 x 50 vertical, then cross battens to gain enough depth for a detail.

 

Below is a snippet of my proposed section, although yet to be updated. The whole pitched roof part will be GRPed together with the gutter detail. Wood cladding will then continue onto the pitched roof. There will be solar PV panels, too. None of this is being reflected in the below rather basic "sketch":

 

 

 

 

 

[bob the builder 2]

BartW

 

Many thanks for sharing this - it is exactly the debate i am having (with myself!) at the moment.

 

I would really like to achieve a hidden gutter but the presence of a wooden frame and cladding are starting to get me worried about water ingress.

 

On the section a couple of quick questions ...

 

- How are you going to run the downpipes (perhaps you have a convenient gable end to work that into?)

 

- Will your wooden cladding be exposed at the top or capped off by the gutter flashing somehow ? 

 

- What are you laying over the GRP on the roof ?

 

Many thanks for your thoughts / time in advance 

 

Bob 

[Dave Jones]

only one thing is guaranteed with hidden gutters. They will block and they will leak.

[Patrick]