Currently, we have a deck of about 15 square meters outside the kitchen, approximately 1.5 meters above the ground. Half of the area has a basement beneath it that is connected to the house's basement. There are signs that indicate there has been some water leakage through the concrete ceiling into that part of the basement.
The previous owner extended the deck to its current size in 1991 by adding a wooden structure. Over the basement part, he placed folded metal sheeting that keeps it watertight. On top is wooden decking.
The wooden construction is built with a weak beam system, on top of which lies raw wood paneling, some form of roofing felt, and then the wooden decking.
The problem:
Firstly, the combination of metal and wooden decking is a bit too high, 22mm decking is screwed into cross-laying 22mm decking. This reaches up to 10mm from the kitchen threshold, which is a problem when there is snow.
The second, more urgent problem is that the sealing with roofing felt on top of the raw wood paneling is leaking and has been for at least 10 years. It doesn't matter if it gets wet underneath. But the raw wood paneling has rotted and now the supporting structure has also started to give way. In other words, it's high time to act.
Right now, I am temporarily reinforcing the rotting beams. I am having a student reception next week, and I don't want to risk it collapsing.
But I am considering a more permanent solution with tiles or granite slabs across the entire area, which would be lower so that the margin to the threshold improves. I'm considering, instead of the wooden part, pouring a concrete deck over that part as well, using existing supports.
The question then is how to make it watertight so it doesn't rain into the basement.
I've understood that you would place some form of membrane, something that resembles roofing felt. But that it should be fully welded with molten tar. It doesn't feel like a DIY job. Is there a variant that doesn't require boiling tar? And that you can place tiles or stone slabs on? And how do you handle the seam between old and new concrete? There's some concern that there might still be small cracks there.
The previous owner extended the deck to its current size in 1991 by adding a wooden structure. Over the basement part, he placed folded metal sheeting that keeps it watertight. On top is wooden decking.
The wooden construction is built with a weak beam system, on top of which lies raw wood paneling, some form of roofing felt, and then the wooden decking.
The problem:
Firstly, the combination of metal and wooden decking is a bit too high, 22mm decking is screwed into cross-laying 22mm decking. This reaches up to 10mm from the kitchen threshold, which is a problem when there is snow.
The second, more urgent problem is that the sealing with roofing felt on top of the raw wood paneling is leaking and has been for at least 10 years. It doesn't matter if it gets wet underneath. But the raw wood paneling has rotted and now the supporting structure has also started to give way. In other words, it's high time to act.
Right now, I am temporarily reinforcing the rotting beams. I am having a student reception next week, and I don't want to risk it collapsing.
But I am considering a more permanent solution with tiles or granite slabs across the entire area, which would be lower so that the margin to the threshold improves. I'm considering, instead of the wooden part, pouring a concrete deck over that part as well, using existing supports.
The question then is how to make it watertight so it doesn't rain into the basement.
I've understood that you would place some form of membrane, something that resembles roofing felt. But that it should be fully welded with molten tar. It doesn't feel like a DIY job. Is there a variant that doesn't require boiling tar? And that you can place tiles or stone slabs on? And how do you handle the seam between old and new concrete? There's some concern that there might still be small cracks there.
I'm not entirely familiar with the construction, but there are materials that are welded with hot air. There are some examples on YouTube, I wouldn't do it myself as it requires experience to get it right. I have an EPDM-based product called Resitrix on my low-slope/flat roofs and I'm very satisfied.
CCHöganäs also has a waterproofing system for outdoor use, I believe this is rolled on.
CCHöganäs also has a waterproofing system for outdoor use, I believe this is rolled on.
Thank you for the answer.
What I want to do is to build a concrete arch of about 7 - 8 square meters, which will be connected to the protruding part of the basement.
What I want to do is to build a concrete arch of about 7 - 8 square meters, which will be connected to the protruding part of the basement.
