Drainage, help!!

[camberg]

Hi,
Our basement is damp and we would like to turn it into a living space. Therefore, we want to install drainage. I have a few questions that I would like answered.

How is it to start draining now in October-November? Is it too damp and should we wait until spring? Or does it perhaps not matter?

We have a gypsum wall with a frame where the sill was measured at about 24% (measured about 1 year ago) according to an inspection. The recommendation is probably to tear down the gypsum walls and paint, right? Anything else?

Now to my actual question: what kind of moisture barrier should we insulate with? I've heard about isodrän, is there anything else you might recommend? I've also read that geotextile fabric is good, is that correct?
What else should we consider regarding the drainage?

Anything else we should think about if we want to make the basement a living space?
Grateful for all answers!!

 

[henryry]

Pordrän or isodrän work just as well. Some people prefer completely moisture-proofed basement walls, and in that case, you use platon mat and cellplast. You'll get plenty of opinions on which is best. Fiberduk is part of the pordrän/isodrän system to prevent soil, etc., from entering the boards. It is not insulation in itself.

When was the house built? Is the foundation insulated at all?

Another tip is to consider if the water and sewage should be replaced at the same time. It's often not much extra work when the excavator, etc., is already there.

 

[henryry]

You can drain year-round. Frost can cause problems when digging, but it is possible.

 

[GoC]

It is completely incorrect to use the term "drain," as that's not what it's about at all. It's about either moisture-proofing the wall on the outside with a tight layer of asphalt, as was done in the past, or applying a platonmat. Same function, i.e., moisture is prevented from entering through the concrete. The alternative is to insulate the wall on the outside and thereby direct the moisture to the insulation material. This is the safest method if you want to furnish the basement and have it heated. But it doesn't really have anything to do with drainage. I would argue that many people replace perfectly functioning drainage pipes when the only problem is an asphalt coating on the basement wall that has become worn out. So not redraining, but improving the wall's moisture protection or adapting it for new basement use is, in my opinion, the correct approach.

 

[camberg]

Pordrän or isodrän work equally well. Some prefer completely moisture-proofed basement walls and then use platonmat and cellplast. You will get plenty of opinions on which is best. Fiberduk is included in the pordrän/isodrän system to prevent soil, etc., from getting into the boards. It is not insulation in itself.

When was the house built? Is the foundation insulated at all?

Another tip is to consider if water and sewage should be replaced at the same time. It's often not much extra work when there are already excavation machines there.

The house was built in '69 and hasn't been insulated before.
Is platonmat and cellplast really enough protection when it's so thin?
Do you mean that isodrän isn't much of an insulation? Please explain

 

[camberg]

It is completely wrong to use the term drain, it's not at all what it's about. It's about either moisture-proofing the wall on the outside with a layer of asphalt, as was done in the past. Or applying a platon mat. Same function, i.e., the moisture is prevented from coming through the concrete. The alternative is to insulate the wall on the outside and thereby move the moisture to the insulation material. This is the safest method if you want to furnish the basement and keep it heated. But it really has nothing to do with drainage. I would argue that many replace perfectly functioning drainage pipes when the only problem is an expired asphalt coating on the basement wall. So not to re-drain, but to improve the wall's moisture protection or adapt it for the new use of the basement is, according to me, the correct approach.

Maybe I expressed myself wrong. I mean that we should insulate/set a moisture barrier from the outside of the basement wall. But merely setting a platon mat or a coating of asphalt isn't that good for a basement used as living space?

 

[GoC]

Maybe I expressed myself incorrectly. I mean that we should insulate/seal against moisture from the outside of the basement wall. But merely using a platon mat or a coating of asphalt is probably not so good for a basement as a living space?

Exactly, if you're going to live there, external insulation is the best solution. If you're going to have it as a basement, asphalt or Platon is perfectly adequate.

 

[henryry]

The house was built in '69 and hasn't been insulated previously. Is a Platon mat and foam plastic really sufficient protection when it's so thin? Are you saying that Isodrän isn't a good insulation? Please explain

No, Isodrän/Pordrän is good as insulation, with similar lambda values as foam plastic. They are different systems: Platon + foam plastic is tight, while Isodrän or Pordrän is based on a diffusion-open technique that allows moisture to come out of the house. There is no consensus on which to choose.

I don't understand what you mean by foam plastic not being enough? You get as much foam plastic as you want for insulation, maybe 100-200 mm or something. Then you put the Platon mat outside.

The reason I thought you wanted to drain was because you wrote it, and insulation is often done in conjunction as you're already digging up. If you have moisture problems in the basement, the drainage or moisture barrier might be bad. You typically see this if the plaster is peeling off, etc.

You write that the house was built in '69 and hasn't been insulated since before. Do you mean that the foundation, i.e., the ground under the concrete floor, isn't insulated? I don't know when they started insulating foundations, but today, insulation is laid under the floor when building new. It's recommended if you want underfloor heating in the basement to avoid heating the ground. However, breaking up all the flooring to insulate is a large project But you asked about "more to think about"

 

[henryry]

Exactly, if you are going to live there, exterior insulation is the best solution.
If you are going to use it as a basement, asphalt or Platon is good enough

Yes, but if you're going to dig around the entire house and place a Platon membrane, you might as well press some foam plastic for better insulation, I think.

 

[GoC]

Well, if you're going to dig around the whole house and install a platon membrane, you might as well add some cell foam for better insulation, I think.

Why is that?
The soil/gravel around the house doesn't have particularly poor insulation capability.
In that case, I would complement with a horizontal row of ground insulation around the house.
There has been some kind of hysteria about insulation and changing drainage pipes.

 

[henryry]

Why is that?
The soil/gravel around the house doesn't have particularly poor insulation ability.
In that case, I would have added a horizontal row of ground insulation around the house.
It has become some form of hysteria about insulation and changing drainage pipes.

To insulate against the wet soil. Foam plastic is cheap in this context.

 

[GoC]

To insulate against the wet soil. Cellular plastic is cheap in this context.

So you've backfilled with wet soil around the basement that you water around the basement? It costs about 10,000 SEK if you're going to apply 5cm XPS insulation around a basement. Sure, a marginal cost when you've already dug up, but does it have any effect that pays off?

 

[henryry]

So you have refilled with wet soil around the basement that you water on around the basement?

If you are serious about the question, I can only say that I refilled with the soil that was there before. I didn't dry it beforehand and it happens to rain here. Then the soil becomes wet. no need to water because of that.

It probably costs about 10,000kr if you are going to add 5cm XPS insulation around a basement. Sure, a marginal cost when you've already dug up, but does it have any effect that pays off?

I'm just saying that I think it's worth insulating when you're at it anyway.

How much is needed depends on what the house looks like, it didn't cost much for me. Regular s100, doesn't that work? Is xps really necessary?

 

[GoC]

If you're serious about the question, I can only say that I refilled with the soil that was there before. I didn't dry it beforehand, and it does happen to rain here. Then the soil gets wet. no need to water because of that.

I'm just saying that I think it's worth insulating when you're at it.

How much is needed depends on what the house looks like, didn't cost that much for me. Regular s100, doesn't that work? Is XPS really necessary?

Regular foam will eventually become completely saturated with water as the cells in the plastic aren't "waterproof," and the insulation ability disappears. Place foam in water, and it will sink over time. So proper ground insulation is what you should use if you have wet masses. You might as well fill with gravel, which insulates nicely as there is room for a lot of air between the stones. If you fill with gravel, then regular foam works quite well and you get a slightly better insulation ability. "Regular" foam is used in dry environments. Hence my comment on whether it is economically justifiable.

 

[henryry]

Common styrofoam becomes completely waterlogged over time as the cells in the foam are not "watertight," and the insulating ability disappears. If you place styrofoam in water, it will eventually sink. So, real ground insulation is what you should use if you have wet materials. You might as well fill with macadam, which insulates nicely as there is room for a lot of air between the stones. If you fill with macadam, regular styrofoam works quite well, and you get a bit better insulating ability. You use "common" styrofoam in dry environments. Hence my comment on whether it is economically justifiable.

Sounds reasonable. But isn't the idea with Platon membrane that no water should enter the boards? Then it's a "dry space," right?