Fixing Pigeon Box Leak

[SLC]

Yet again I seek the help of the kind people on this form.

We have pigeon boxes on the roof as shown in the picture. Light is let in by a sheet of glass measuring 16” by 6”. The internal wooden trim is bonded to the inside of the glass using some form of permanent sealant. Consequently, removal of the glass is not really possible as the trim is bonded to the glass and the metal box. The outside sealant is of different material and has been applied later in life. Unfortunately, water is leaking in at the bottom corners where the rain accumulates and it is clear to me that the outside sealant has perished i.e. not stuck to the joint between glass and box frame. Somehow it is also getting past the internal sealant holding the trim to the glass. The simple naïve solution would appear to be remove the exterior sealant which has failed using a Stanley knife and reseal. However, while the sealant has glass to adhere to, the pigeon box material is basically the thickness of the box so there is not much to “adhere to” in the other corner. 
Does anyone have any suggestion as to how I could seal the joint to prevent leaks and which sealant I should use? I do not think it is possible to remove the glass from behind and reseal everything.

 

[magnetman]

Maybe pieces of 3mm perspex cut to exactly the right size then drop them in on top of the glass with a bead of pu sealant around the edges. 

 

A bit of a bodge I admit but it would probably stop the leaking. 

 

the fact the glass is below the level of the frame itself seems to be a fundamental design flaw as water will just sit there. 

 

 

[blackrose]

I'd probably use a bead Stixal crystal clear on the outside, wherever you think water is getting in. It will bond to glass. Available at Toolstation, Amazon, etc.

 

https://www.toolstation.com/stixall-adhesive-sealant/p77137

 

Make sure that any flaking surfaces are sanded back and cleaned. If the surface is sound wipe it over with a dab of white spirit on a clean cloth first to make sure there's no oil or grease.

 

 

Edited May 7, 2023 by blackrose

[BEngo]

Unfortunately I think the only permanent solution will be to redo the interior trim after removing the trim and glass.   The seal has probably failed a while ago, hence the external sealant.  There is a danger that not only will there be damage to the trim, rust will set in behind the sealants.

 

Re-seal with a proper glazing sealant.  Ideall get one suitable for Crittal style steel windows as that will be designed to handle movement of the steel.

 

In  the short term you could give it a good ladling of Captain Tolleys Creeping Crack Cure, available on the web.

 

N

[blackrose]

4 minutes ago, magnetman said:

Maybe pieces of 3mm perspex cut to exactly the right size then drop them in on top of the glass with a bead of pu sealant around the edges. 

 

A bit of a bodge I admit but it would probably stop the leaking. 

 

the fact the glass is below the level of the frame itself seems to be a fundamental design flaw as water will just sit there. 

 

 

Yes, but why not stick the perspex onto the top of the frame with the sealant rather than dropping it into the recess? Again it's a bodge, but at least the water would run off and not sit inside. 

[Bee]

This is one of those things that happens when the glass is recessed, those corners or the bottom just rot out or rust out. Is yours steel? I have wooden pigeon boxes, all nicely varnished and I fixed a clear perspex or polycarbonate sheet over the whole 'leaf'. I did this partly for safety - I could imagine someone tripping on the roof and putting a hand through the glass but also because of the trapping water thing. I used black foam tape sticky both sides and it works well

[magnetman]

3 minutes ago, blackrose said:

 

Yes, but why not stick the perspex onto the top of the frame with the sealant rather than dropping it into the recess? Again it's a bodge, but at least the water would run off and not sit inside. 

That is certainly what I would do but I don't have tidy boats. This boat looks tidy and I think done external like that it could detract somewhat from the appearance. 

 

Actually thinking about it the best way would be to put in some wood strips to raise the perspex to the level of the top then put it in and get it flush. That would be nice and put some of those moisture absorbing crystals in the gap. 

 

 

[Alan de Enfield]

Indirectly solves the problem :

 

We had a cover made for ours (it didn't leak, but just planning ahead) the cover had 'windows' incorporated which meant we got the light, and if we wanted to have it open and 'get some air in' the cover was simply lifted off and it could be used as normal.

Not the most elegant of solutions, but functional.

 

 

 

[SLC]

Thanks for the comments so far. To clarify, the box is metal.

[magnetman]

I've seen one of these where someone had bent a single piece of perspex over the top of it in a half tube sort of arrangement. Looked quite good but vulnerable to the wind I think. 

[toffeedanish]

I had a similar issue. My solution was to use gutter sealent: relatively cheap, black so doesnt draw attention to itself, lasts a relatively long time, bonds to both surfaces. Masking tape on the glass for straight lines. Knife off at a 45 degree angle so there is nowhere for water to accumulate. All still good two years later.

[David Mack]

Does water pond along the bottom of the glass? If so you need to remove and replace the exterior sealant along the bottom edge so that the slope on the sealant is away from the glass. That does mean that the sealant will come further up the glass, which will reduce the area of clear glass.

 

Alternatively is it possible to remove the glass and replace it with a smaller piece set flush with the outside edge of the frame? That will require changes to the rebate and inside trim arrangements.

[Tam & Di]

6 hours ago, Alan de Enfield said:

 

 

I had a cover made pretty much the same as Alan's (but a tidier fit 😁). Mine also had rectangular clear panels which were pretty much the size of the rectangular glass they covered. It was easily removable, but in reality I seldom removed it other than when I painted the roof and revarnished the pigeon box. We did have alternative opening Lewmar hatches though.

 

Tam

Edited May 7, 2023 by Tam & Di