Have just had a roof fitted over the outside  Thai Kitchen and it is leaking where the gutter meets the outside wall of the property.

 

Our builder has been back to re-seal under the gutter, he just used a tub of acrylic sealant and smeared it between the wall and the underside of the gutter. There are still some small leaks, especially when it tips down like it has recently.

 

Any recommendations for a good sealing product and tips on how best to get it to seal properly ?

A good sealant is polyurethane PU.

 

I don't really understand what is leaking though, is the leak along the length or is it at the end?

If you post some photos that will be helpful. What specific roof tiles? What type of rain gutters? I assume the rain gutters are attached to fascia board, but your photo will help. There are far more professional sealing products widely available in Thailand OTHER than acrylic sealant. Dr. Fixit, Lanko, Sika and Lanko are four companies that offer more professional solutions to leaks on a house in Thailand. All  four have product catalogs in Thai and catalogs in English. 

Yeah, a few photos would help.

 

There are a number of sticky-back roll products as well as splodge-it-in-the-gap tubes which will do the job, which you use depends upon what you are actually sealing.

Thanks for the replies, Builder has used a splodge it in the gap job, will post some pics tomorrow when work out how.

On 08/05/2018 at 10:52 PM, Kieran00001 said:

A good sealant is polyurethane PU.

 

I don't really understand what is leaking though, is the leak along the length or is it at the end?

Along the length of the gutter where it abuts the rear wall.

8 hours ago, Bangkokhatter said:

Along the length of the gutter where it abuts the rear wall.

 

Then the gutter is not positioned correctly, it is too small for the roof, or the rooffing sheets are not projecting far enough into the gutter, you should not need to seal along the length of a gutter.  One way to correct this may be to slide some roofing felt under the bottom of the roofing sheets and down into the gutter.

19 hours ago, Bangkokhatter said:

Along the length of the gutter where it abuts the rear wall.

I had a similar problem, solution - can of expanding foam spray, fill up the backside, let it dry and trim off excess with a knife. Worked for me .........

12 hours ago, Kieran00001 said:

 

Then the gutter is not positioned correctly, it is too small for the roof, or the rooffing sheets are not projecting far enough into the gutter, you should not need to seal along the length of a gutter.  One way to correct this may be to slide some roofing felt under the bottom of the roofing sheets and down into the gutter.

 To be fair to the builder the rear wall which  marks the Moobahn boundary is not very straight so not easy to position correctly. 

 

You do have a point about the overhang though, it's about a 4 inch stainless gutter and the overhang is only about 1.5 inches.

1 hour ago, CGW said:

I had a similar problem, solution - can of expanding foam spray, fill up the backside, let it dry and trim off excess with a knife. Worked for me .........

I remember using something similar on the crappy walls i had in my UK house. Do you have a name and where i can buy it please ?

2 minutes ago, Bangkokhatter said:

 To be fair to the builder the rear wall which  marks the Moobahn boundary is not very straight so not easy to position correctly. 

 

You do have a point about the overhang though, it's about a 4 inch stainless gutter and the overhang is only about 1.5 inches.

 

Capillary attraction results in water running back on the underside of the roofing before it falls off, the roofing should extend beyond halfway into the gutter, so that will be the cause if its only 1.5" as it should be about 3".  If you can't move the gutter closer to the roofing then its either get some sheets cut to slide under and extend the length of the roof an inch and a half, or put some felt under the roof that extends out into the gutter.

Not the best pictures but you can see where the builder has just chucked some acrylic sealant in the gap.

 

@ Kieran i think there are 2 problems, 1 is the short overhang causing water to come over one side and the other is the join where the gutter meets the outside wall. Access to roof panels to install felt sheeting will not be easy.

1 hour ago, Bangkokhatter said:

I remember using something similar on the crappy walls i had in my UK house. Do you have a name and where i can buy it please ?

Its available at most DIY stores, expandable foam, its not the easiest product to apply so if you do use it wear gloves!

 

The PU spray foam is going to be a nightmare to get in there, and probably won't look too good.

 

I would be tempted to try some of the sticky-back flashing on a roll. We got some black plastic stuff about 3" wide to seal our patio roof to the wall.

 

Several brands, looks a lot like wide duct-tape.

On 09/05/2018 at 5:17 AM, Crossy said:

Yeah, a few photos would help.

 

There are a number of sticky-back roll products as well as splodge-it-in-the-gap tubes which will do the job, which you use depends upon what you are actually sealing.

This is one of the sticky products 

You need to check you have plenty of fall and down pipes to get the water away fast as you have blocked the overflow with the sealing on the wall so the excess water will flow back under the roof


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The sticky stuff we used was Sika Multiseal AP, came from MegaHome, not particularly cheap.

 

https://tha.sika.com/en/solutions_products/02/02a008/02a008sa17.html

 

The expanding foam, I imagine, would do the job but I can also envisage it getting out of control and looking a bit of an eyesore !!

I used it once years ago to fill in a hole in my roof between fascia and tiles where birds were entering and nesting but I was able to squirt it in, trim it and paint it so the results were good, in the OP’s case it would be difficult to tidy up.