Rain overflow

Hi - I have perpetual issues on very heavy rain ( downpours) I think I’ve worked out the problem but don’t know the solution.

1. Rain comes from the left to R on the LH roof , then there is a say 2” down pipe and drop into the gutter below which then feeds into the gutter which then turns right at the base of the lead valley and goes off to the right into a new soakaway.

A. Rainfall off the roof on the left doesn’t reach the gutter and falls short, down the wall and is like a sheet in front of the window ( the one to the left of the door, below the valley) I can address that probably by redoing the last few rows of tiles and putting on new felt or whatever they use these days, so that the felt goes into the gutter. This is the minor issue.

B. Rain overflows at the Y where the lead valley comes in. I think this is because the water coming from the left can’t get away fast enough and hits the torrent coming down the valley. Must be a classic issue of water coming from all directions and banging into itself. The water then streams over the gutter like a waterfall and onto the step and then into the house.

I want to put up a glass canopy one day, like a porch roof, somehow over that door one day - so you don’t get wet opening the door. Again, this is secondary to firstly stopping the water overflowing.

2. Water overflows the gutter and comes in through the windows. The kitchen ceiling some 3 feet away from the window ( along a supporting girder) is stained from water ingress over the years. This isn’t from the window directly, it’s getting in somewhere and leaching along.

Again, I think it’s a question of water coming from 2 different directions and is ricocheting off itself down the window.

Any ideas gratefully received - taken me 5 years to guess at the problem. I’m thinking of diverting the gutter to flow the other way and did another soakaway for the first problem. Or for both problems is there such a thing as a big hopper thar everything could flow into. Or larger diameter guttering? So grateful to anyone that can help solve this at last. Thanks.

I reckon from a quick calc that the gutter is just too small. There are tables out there e.g. https://www.polypipe.com/sites/default/files/Rainwater_Design_System_Selection.pdf Just from pix I reckon you have an effective roof area of around 40sqm. Plus you have an angle and end drainage which both restrict capacity. My opinion is that a larger section gutter is required.

I have just used some galvanized steel from here https://www.guttersupplies.co.uk/steel-gutter-c-34/ on a new garage - I hate plastic gutter. Might be worth a look.

The velux bottom left looks iffy, You could be getting ingress from that and running down.

Bottom tile course is incorrect and could be (probably is) allowing water back under the tile laps , Norfolk Pantiles need to be correct to avoid issues

There are plenty of hopper options if you move away from plastic.

Awesome replies - thank you. I would never have thought of changing the whole guttering. Why don’t you like plastic - no good or appearance? The joints have gone too - because water rested in it, then froze in the winter, joints broke, caused icicles and just got worse and worse.

Plumber / builder on this house must have been useless - previous people had been in 10 years and said they had the septic tank emptied every 3 months. Alarm bells - we checked and outfall drains were literally, no exaggeration, as new - they’d never worked. They went up hill. Also when it rained heavily, the downpipe that is connected to this guttering I’m talking about, used to bubble up. Again, underground pipe went uphill - we ended up creating a brand new soakaway.

Thanks again for all the advice and links.

Datarebal - what’s wrong with the bottom course?

They are laying below the recommended pitch for the roof tile. In places nearly flat. If you take into consideration the bulk of the roof is a good pitch 40 - 45 degrees
Rain running down from above is likely to back up under the tile lap of the second course..

If you know the makers you could send a picture and ask their opinion ... It is wrong.

The gutter has its issues as you are aware.

https://rooftileassociation.co.uk/tech_lib/pantiles-clay-and-concrete/

Note the tile plain in the image showing eaves.. ignore the vent for now

Oh, right, thanks. So many people don’t do things properly. We should value, and pay for, experts at their craft / trade. Thanks again.

Crikey, thanks for the link to the Rooftile Assoc. I’m definitely going to get an expert to do it properly and do it once and get it sorted - not a question of patching and bodging.