ᐅ Seal the bottom of the garage door before laying the screed (flooring layer).

Hello everyone,

Our garage door on the backside has now been installed. The window installer was involved, even though it’s an electrical door. He professionally sealed the sides and top. Since a screed will still be applied in the garage, there is currently a gap under the door. This needs to match the thickness of the screed. The window installer temporarily placed a few wooden blocks underneath to prevent the door from just hanging there.

Today on the construction site, I was asked how the sealing is supposed to work at the bottom before the screed is applied. I assumed that the screed would be installed first and then the sealing would be done on top of it. However, he said that it also needs to be sealed before the screed using a sealing tape or similar.

But how do I best do that when there is no floor at the bottom yet? Where and how should I apply the sealing?

You need to foam the gap, and then there is a so-called EMPD TAPE. You must use this tape to seal your joint, or you can go to a building supply store and get further advice there.

By "at the bottom," he means the concrete floor, so you need to install an EPDM strip (sorry, I wrote it wrong above) between the concrete floor and the door track.

I understand the use of tape. They also left some on the construction site. But the gap is about 10cm (4 inches). Tape alone won’t hold there.

That’s exactly my concern. I thought they would lay the screed up to under the door, which would eliminate the gap. But apparently, that’s not the case. Also, I need to seal before the screed. But how do you seal such a large gap?

Actually, the door installer needs to ask for the height of the top edge of the screed so that the bottom door threshold lines up with the screed.
Maybe a photo of the door?

Currently no photo available. I will be on site again tomorrow and can provide one then.