Exterior caulk wears off frequently

[akinun]

Hello everyone,

This question follows from a previous window leak question (Why are my window corners wet when it rains?) but I think caulking is a more general topic, so thought maybe it is more appropriate to post here.

After inspecting the exterior for caulking damage and not finding any visually, I hired an infrared camera heat loss detection contractor, who actually did find some caulking problems that were not visible to the eye.

The problem with the following photos is that this caulking was redone twice in the last two years. The first original caulking was peeling off, so this summer, we used a different contractor with a different caulk brand to redo all windows. And it is peeling again.

So now my question has changed to: "why is my caulking wearing off so quickly?"

First polyurethane caulk we tried was Soudal: Soudaflex 40FC Sealant - Sealant Supplies Ltd
and the second one was a locally popular and high rated brand: DAYSON EXTRA POLYURETHANE SEALANT

Both are peeling off or having punctures within a year. What could be the problem? Possible culprits:

- This is a coastal region. Caulking was done in summer so probably done during high humidity. Or related - the caulking was done during a humid summer period, maybe that is causing this?

- The leaks come from the northern wall of the house. The area receives heavy rain with northern winds, so this may wear off caulk faster

Any pointers or thoughts hugely appreciated.

Attachments​

 

[user 4883]

You'll have to remove all the old layers of caulk and then apply this. You'll never have another problem.
Commercial Grade Sealant

 

[Sparky617]

Also, caulk is the absolute last line of defense against leaks. You want the water diverted away with flashing across the top of the window, and proper slope/drainage around the sill of the window.

 

[Steve123]

So now my question has changed to: "why is my caulking wearing off so quickly?"

I am figuring that at one point, somebody used silicone. Nothing sticks to cured silicone. Can be very difficult to remove all traces.

 

[akinun]

You'll have to remove all the old layers of caulk and then apply this. You'll never have another problem.
Commercial Grade Sealant

Thank you very much - is there a product you'd recommend to remove previous polyurethane caulk easily? Like a softener?

Also, caulk is the absolute last line of defense against leaks. You want the water diverted away with flashing across the top of the window, and proper slope/drainage around the sill of the window.

You are absolutely right, but unfortunately, most European windows (especially continental architecture) have no flashings. Especially when I used to live in the UK countryside, this was a common problem. Modern homes have flashings, but the majority of older buildings unfortunately have none. See: . To that end, I need to think of ways to divert water away without removing and reinstalling windows

I am figuring that at one point, somebody used silicone. Nothing sticks to cured silicone. Can be very difficult to remove all traces.

Quite possibly; any suggestions on solutions or softeners that make it easier to remove silicone?

 

[Steve123]

Quite possibly; any suggestions on solutions or softeners that make it easier to remove silicone?

Not really. I have done it on a shower. Its hard work.

 

[Tailgunner]

I would think a heat gun would soften it and make it easier to remove.