I am building an unheated but insulated sunroom with an insulated wood joist structure.
The order of materials in the construction from top to bottom (according to the designer) is:
* vinyl click flooring
* 22mm moisture-resistant particle board
* 0.2mm plastic film
* 220 mm mineral wool insulation
* bottom joist boards
(When the designer drew the sunroom, we didn't know we wanted vinyl click)
My question is whether it would be possible to swap the particle board and the plastic film, so that you get a tight layer directly under the vinyl click flooring.
Apparently, any water that stands on the floor can leak down through the joints. Even if the vinyl flooring can handle it, the floor particle board might not.
What do you think? Is it an OK change? Or should I keep it as it is according to the drawing?
What do you mean by ventilated? It's almost completely airtight from below, and the little that does make its way through, I think it's better if it can dry out than get stuck against a potential plastic sheet!
I am in the process of building an unheated but insulated sunroom with an insulated wooden floor structure.
The order of materials in the construction from top down (according to the designer) is:
* vinyl click flooring
* 22mm moisture-resistant particleboard
* 0.2mm plastic film
* 220 mm mineral wool insulation
* subfloor panels
(When the designer drew the sunroom, we didn't know we wanted vinyl click)
[image]
My question is if you could swap the particleboard and the plastic film, so you get a sealed layer directly under the vinyl click flooring.
Apparently, any water that remains standing on the floor can leak through the joints. Even if the vinyl floor can handle it, the particleboard may not.
What do you think? Is it an OK change? Or should I keep it as it is according to the drawing?
Hi Anders.
You must have plastic!!! And it should be completely sealed without any holes whatsoever.
The temperature drop is linear against the thermal resistance
through the floor structure, and therefore, condensation will form on the plastic if it is placed too far out in the construction.
plastic = warm side
Condensation = cold side
Negative pressure = good, i.e., ventilation.
Natural draft = positive pressure = mold and condensation.
If you do as others suggest here and don't use plastic, then the temperature on both sides of the insulation must always be the same! And then you have to insulate the foundation from the outside, which is extremely expensive compared to the plastic.
I recommend you not listen to the suggestions you've received in this thread, as they are a 110% guarantee that your new room will mold! You can place the plastic beneath a 10 mm foam board on the particleboard instead. And place the vinyl click flooring on that. But consider doors, rails, and thresholds. If you won't use plastic, you could also omit insulation entirely; everything depends on degree hours, U-values, heating system, temperature difference, ventilation system, north/south orientation, foundation, and thermal bridges. Not something for amateurs to speculate about. We have a 30% building error rate in Sweden due to amateurs. Your detail is incorrectly drawn, by the way. To fasten the particleboard, it needs to be screwed, and then holes will be made in the plastic if it's placed where it is on the drawing. The correct placement of the plastic should be on top of the particleboard, but under the finished coating as you yourself suggest.
An alternative is a welded waterproof membrane that replaces the plastic. Since you don't intend to heat the space, no insulation is needed. There will be mold if you have plastic and insulation but no heat. Imagine placing a T-shirt in a plastic bag on the lawn and putting some insulation in the bag as well. And then you want to use your T-shirt four times a year and put it back in the bag every time and tie it up... the same physics and laws of nature apply in your sunroom.
I would like to ask you to elaborate a bit, with regards to, for example, a spring/autumn day.
Cold at night and warm during the day.
In an uninsulated space with humidity that will vary.
Where should the plastic be placed considering that the conditions change throughout the day?
Warm side = Outside = day
Warm side = Inside = night
Hello everyone, thank you for all the discussion so far.
I might clarify that this concerns a glazed patio/winter garden.
When the draftsman made the drawing, it wasn't entirely decided whether we would have underfloor heating or not, but as of now, we believe we will skip the underfloor heating and possibly install auxiliary heating to keep it frost-free inside during the winter.
The floor, walls, and roof are insulated to retain any radiant heat/sun as well as any auxiliary heat.
We have now acquired vinyl click flooring that is water-resistant, but according to the supplier, it can "leak water through to the underlying boards at the seams." So I'm mostly considering having a plastic film as a simple moisture barrier to prevent any issues that might arise if, for some reason, there is water on the floor for an extended period, such as if a child left the sliding doors open during a sideways rainstorm.
So maybe the question should really be; would it hurt to have an age-resistant plastic between the vinyl floor and the chipboard as a simple moisture barrier for any potential water intrusion?
(From what I can interpret from your other comments, if you are to have the plastic film, it should be on "the warm side" if anyone.)
The problem with your conservatory is the theory.
What we disagree on is whether the theory follows the same moisture movement pattern in a room that is colder than the surroundings compared to a living space that maintains 20 degrees.
Moisture movement occurs naturally due to the environment; you just don't want the condensation point to happen somewhere in the insulation. If it does, you want the moisture to move out of the beams at some point. If it happens upwards and there is a plastic there, does the plastic protect or create problems?
It will obviously happen that the room becomes colder than the surroundings.
Some claim that an open solution without plastic is safer.
This sounds like a room that will almost always be warmer than outside, and if it's also meant to have plants there, moisture will be added. I would definitely put a moisture barrier on the inside. It can absolutely be on top of the chipboard, the downside is that you increase the risk of damage during the work.
I will place a plastic sheet under the floor, but above the chipboard.
This is also the solution that is easiest practically given the conditions with the already built frame and glass panels.
I also believe that the room will be warmer than the surrounding environment most of the time.
Anders243 said: