ᐅ Installing vinyl flooring in a new basement. How to ensure it is waterproof?
Created on: 22 Jan 2023 20:02
J
joltHello everyone,
We would like to have vinyl flooring installed in the basement of our newly built house. The basement is constructed as a waterproof concrete shell (“white tank”), so I don’t really expect any water, but you never know. In the laundry room, there is a floor drain in the center.
The current floor structure is as follows:
However, if water actually accumulates in the basement, I assume it will become an issue at the wall edges. In that case, you would probably need to proceed as in a bathroom, using sealing tape and a waterproof membrane? This would be quite a bit of extra work for the entire basement, but probably in excess of what’s necessary.
How would you approach this? What should I keep in mind?
Thank you.
We would like to have vinyl flooring installed in the basement of our newly built house. The basement is constructed as a waterproof concrete shell (“white tank”), so I don’t really expect any water, but you never know. In the laundry room, there is a floor drain in the center.
The current floor structure is as follows:
- Perimeter insulation
- Concrete slab
- Bitumen waterproofing membrane
- PU (polyurethane) insulation
- Underfloor heating
- Cement screed
- Sanding the screed
- Priming
- Self-leveling compound application
- Sanding again??
- Vinyl gluing
However, if water actually accumulates in the basement, I assume it will become an issue at the wall edges. In that case, you would probably need to proceed as in a bathroom, using sealing tape and a waterproof membrane? This would be quite a bit of extra work for the entire basement, but probably in excess of what’s necessary.
How would you approach this? What should I keep in mind?
Thank you.
Hello,
Is this supposed to be installed as sheet material? If it really needs to be watertight, then you also have to have the seams between the sheets sealed.
But if you have a floor drain anyway, what exactly could happen that would suddenly create a swimming pool down there? Drain clogged and the washing machine connection breaks while you’re on vacation? I think that’s a bit far-fetched, and if it does happen, you would have building insurance that you’ve already checked covers such situations.
I wouldn’t do anything more. Maybe just install a water alarm next to the usual suspects like the washing machine. And install baseboards with rubber sealing lips to prevent spilled water from flowing into the screed, which stops larger amounts of water from penetrating.
Is this supposed to be installed as sheet material? If it really needs to be watertight, then you also have to have the seams between the sheets sealed.
But if you have a floor drain anyway, what exactly could happen that would suddenly create a swimming pool down there? Drain clogged and the washing machine connection breaks while you’re on vacation? I think that’s a bit far-fetched, and if it does happen, you would have building insurance that you’ve already checked covers such situations.
I wouldn’t do anything more. Maybe just install a water alarm next to the usual suspects like the washing machine. And install baseboards with rubber sealing lips to prevent spilled water from flowing into the screed, which stops larger amounts of water from penetrating.
For a short time, I had an unwanted indoor pool in the basement bathroom (washing machine supply line was defective, leaked, flooding the room to about 30cm (12 inches) high).
The flooring was vinyl in a solid sheet, an early predecessor of click-lock flooring (overlapped and glued). After pumping out the water and drying, everything was back to normal.
However, the walls were fully tiled, and the vinyl was laid without a sealing joint at the edges. So, some water got underneath.
Way too much effort and cost. As others mentioned before, just use a washing machine with a water sensor and that’s it.
The flooring was vinyl in a solid sheet, an early predecessor of click-lock flooring (overlapped and glued). After pumping out the water and drying, everything was back to normal.
However, the walls were fully tiled, and the vinyl was laid without a sealing joint at the edges. So, some water got underneath.
Way too much effort and cost. As others mentioned before, just use a washing machine with a water sensor and that’s it.
Hello questioner.
With the construction method you described, the drainage can only be considered an "emergency drainage." Assuming proper installation, the floor drain was certainly sealed to the bitumen membrane.
If a bucket of water tips over, this is fundamentally a "damage event not corresponding to the contractual use." Such situations can occur anywhere in the house and do not require special technical measures in execution!
Everything planned with a "rubber sealing lip," etc., is rather a form of self-deception. Technically, this does not make sense at all!
The described construction assumes, from a planning perspective, a room with increased requirements: a living space has been planned and executed accordingly.
Not a (secondary use) laundry area!
When installing a bathroom, the rules according to DIN 18534 apply.
This means that a bathroom is classified under water exposure class W1-I. This corresponds to waterproofing over bathtubs and showers in bathrooms, floor surfaces in domestic areas with floor drains, and floor surfaces in bathrooms with or without drains without high water exposure from the shower area.
The floor surfaces (and only these) inside the shower fall into the next higher exposure class W2-I (floor surfaces with drains or channels).
Here, wall surfaces and floors must be waterproofed accordingly (for example, with liquid-applied membranes), and the floor-to-wall transitions must be fitted with sealing tapes. But under no circumstances the entire floor level!
To answer your last question:
Yes, the screed surface must be ground, dust extracted, and primed. Then the leveling compound is applied, which is usually sanded again (to remove any lumps or "pimples").
Only at this stage are the waterproofing measures carried out.
Also remember that sealing collars must be used at pipe penetrations and integrated into the waterproofing layer!
------------------
Good luck and all the best: KlaRa
With the construction method you described, the drainage can only be considered an "emergency drainage." Assuming proper installation, the floor drain was certainly sealed to the bitumen membrane.
If a bucket of water tips over, this is fundamentally a "damage event not corresponding to the contractual use." Such situations can occur anywhere in the house and do not require special technical measures in execution!
Everything planned with a "rubber sealing lip," etc., is rather a form of self-deception. Technically, this does not make sense at all!
The described construction assumes, from a planning perspective, a room with increased requirements: a living space has been planned and executed accordingly.
Not a (secondary use) laundry area!
When installing a bathroom, the rules according to DIN 18534 apply.
This means that a bathroom is classified under water exposure class W1-I. This corresponds to waterproofing over bathtubs and showers in bathrooms, floor surfaces in domestic areas with floor drains, and floor surfaces in bathrooms with or without drains without high water exposure from the shower area.
The floor surfaces (and only these) inside the shower fall into the next higher exposure class W2-I (floor surfaces with drains or channels).
Here, wall surfaces and floors must be waterproofed accordingly (for example, with liquid-applied membranes), and the floor-to-wall transitions must be fitted with sealing tapes. But under no circumstances the entire floor level!
To answer your last question:
Yes, the screed surface must be ground, dust extracted, and primed. Then the leveling compound is applied, which is usually sanded again (to remove any lumps or "pimples").
Only at this stage are the waterproofing measures carried out.
Also remember that sealing collars must be used at pipe penetrations and integrated into the waterproofing layer!
------------------
Good luck and all the best: KlaRa
Hello everyone,
Thank you for your contributions.
We plan to install vinyl planks, not sheet vinyl. My main concern is not so much a defective washing machine or similar, but rather a (minimal) risk of flooding and water entering through the basement exterior door. There is a drain in front of it, which connects to the sump pit. However, if the sewer system becomes overwhelmed during heavy rain and the pump cannot handle the volume—meaning the pipe up to the backflow level is full—the sump pit could overflow, or more likely, water will push up at the highest point, which is the floor drain in the laundry room. I don’t know how likely this scenario is, but extreme weather events are clearly increasing. Covering the terrace and basement stairs would eliminate this weak spot and is under consideration.
As most of you have suggested, I will not plan any additional measures, such as sealing strips. Under normal circumstances, it should only involve some splashing water or small incidents, and everything should be fine.
Thank you for your contributions.
We plan to install vinyl planks, not sheet vinyl. My main concern is not so much a defective washing machine or similar, but rather a (minimal) risk of flooding and water entering through the basement exterior door. There is a drain in front of it, which connects to the sump pit. However, if the sewer system becomes overwhelmed during heavy rain and the pump cannot handle the volume—meaning the pipe up to the backflow level is full—the sump pit could overflow, or more likely, water will push up at the highest point, which is the floor drain in the laundry room. I don’t know how likely this scenario is, but extreme weather events are clearly increasing. Covering the terrace and basement stairs would eliminate this weak spot and is under consideration.
As most of you have suggested, I will not plan any additional measures, such as sealing strips. Under normal circumstances, it should only involve some splashing water or small incidents, and everything should be fine.
@ jolt:
Let’s put it this way: If water actually enters the floor structure—whether from heavy rainfall or a washing machine—then you will face—hopefully not!—much more serious issues related to drying measures in a heated screed construction than just the surface covering!
Therefore, I would strongly recommend addressing this safety risk (flooding of the living area) immediately.
It is not enough just to hire some restoration company for forced drying of the insulation material beneath the screed.
The water coming in from outside—it’s neutral to say it this way, but understandable—is far from drinking-quality water. It contains a variety of contaminants, both solids and dissolved substances that you definitely wouldn’t want in your home.
In most cases, if the flooding originates from the sewage system, a complete rebuild will be necessary (meaning full removal of the heated screed and insulation). Forced drying alone will never be effective as the only measure!
The scenario discussed here is not theoretical but a practically possible situation.
That’s why my suggestion is to first secure the drainage system against backflow.
---------
Best regards, KlaRa
Let’s put it this way: If water actually enters the floor structure—whether from heavy rainfall or a washing machine—then you will face—hopefully not!—much more serious issues related to drying measures in a heated screed construction than just the surface covering!
Therefore, I would strongly recommend addressing this safety risk (flooding of the living area) immediately.
It is not enough just to hire some restoration company for forced drying of the insulation material beneath the screed.
The water coming in from outside—it’s neutral to say it this way, but understandable—is far from drinking-quality water. It contains a variety of contaminants, both solids and dissolved substances that you definitely wouldn’t want in your home.
In most cases, if the flooding originates from the sewage system, a complete rebuild will be necessary (meaning full removal of the heated screed and insulation). Forced drying alone will never be effective as the only measure!
The scenario discussed here is not theoretical but a practically possible situation.
That’s why my suggestion is to first secure the drainage system against backflow.
---------
Best regards, KlaRa
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