Butyl Flashing

Ricky, what are you trying to accomplish. I ask because I had to seal between the base of my Observatory and the concrete base and I had to resort to Hi Tech stuff that you could use in wet and also would "set" in water.

 

I tried bitumen flashing and ordinary sealer paint but couldn't get it to grip on wet concrete or even set in any wet. When the Observatory was built onto the concrete base it was raining and the sealant the people brought was useless for applying in the wet. This is what I was trying to seal.......




I originally bought brand new Bitumen tape, sealant and roof repair paint not thinking I would have any real problems......it was useless. So I did a bit of research to find sealant that would set in water to fill in the gap and a paint that would go over the sealant in water and set. I found Geocel "The Works" Wet and Dry Sealant


and the paint I used to go over it to complete the seal was Thompson's Emergency Roof Repair Mastic


I had to use enough seal into the gap between the Observatory and concrete base to cover over 30 feet around the base, but the Tin of Thompson's Mastic was more than enough.
It was/is important that no water seeped into the Observatory from the base as there is a power system and also Telescopic equipment in there so I made sure that what I eventually used would work and last years. So maybe conventional bitumen isn't the way to go, Ricky, you might want to spend a few extra pennies for a good job and one that will last up to ten years before you used the Mastic again to paint over the sealant.

 

Hi Ricky, no, it's the roof that revolves


There was a initial gap between the base of the Observatory wall and the concrete base so that water would seep in between and I had to keep the floor of the Observatory completely dry before laying a membrane and 2 inch thick rubber tiled floor

Firstly, you shouldn't try just the sealant on it's own but use it in conjunction with the Mastic, i.e: applying the sealant and then "painting" the Mastic over it. I used Masking Tape as a guide and to stop the application of the Mastic becoming messy. Using both guarantees a double barrier and the Mastic will give you that near 10 year guarantee, plus all you have to do is repaint over it when needed and it also protects the sealant giving it a virtually infinite life.