Is pressure-treated suitable as bottom sill against slab?

[Bogeymannen]

I have hired a company to build an extension to my house with a bathroom and laundry room. They have now gotten to the point where they have poured and begun the framework, but to my surprise, I discovered they were using pressure-treated wood against the slab... this despite the fact that when they asked, I said I wanted "regular" wood with a moisture barrier. The problem is that they are building with standing 145 and then laying 45x45 to nail the panel on. The bottom 45x45 is then partially against the slab without any moisture barrier... What should I do? :eek:... is this an okay way to build? Hoping for quick answers

 

[MoN]

No, tell them to redo it. The timber should not have direct contact with the concrete. Pressure-treated timber should be avoided in house constructions (don't even know if it's allowed).

 

[andersmc]

There must be a moisture barrier. Even if the treated wood might not rot, it will smell when it gets moist.

 

[Gladh]

Everyone who has a 70s house with pressure-treated sills knows that it's not a good idea. Just like Anders says, it doesn't rot but it smells musty. Most people with 70s houses have replaced their pressure-treated sills today. Redo it, do it right.

 

[mattiasp]

I claim that you can indeed have pressure-treated wood in the sill, but there must be sill paper. The idea that pressure-treated wood would be dangerous in the sill is nonsense.

So sill paper is the important thing. Roof felt works fine if you have some lying around.

 

[ppalm]

I claim that you can indeed have pressure-treated wood in the sill, but there must be sill paper. The idea that pressure-treated wood would be dangerous to have in the sill is nonsense.

Sill paper is the important thing. Roofing felt can be used if you have some lying around.

I agree with mattiasp

the most important thing is to eliminate the root cause of moisture in the sill, and then the sill won't get wet and smell.

 

[Mikael K.]

In your position, I would have absolutely insisted that they redo it.

Why not Nivellreglar (I think that's what they were called) so that there will never be a problem?

Wood against a slab is not good, pressure treated is even worse. The houses from the 70s have taught us that...

 

[mattiasp]

I don't understand that. Why would it be better to have a rotten, non-impregnated sill with no bearing that smells bad, than to have a damp, pressure-treated sill that smells bad with good strength?

 

[styrman1]

nivellreglar as a sill???'No.

 

[ClasseClas]

Regardless of whether a treated or untreated syll is used, the important thing is that the syll is moisture-proofed with syllpapp or equivalent against the concrete slab. The use of treated syll sometimes is probably mainly because the syll is installed days before the prefabricated walls are delivered from the factory and mounted on the foundation and syll. I have treated syll that stands dry, so it doesn't have to be a problem with that solution.

 

[Mikael K.]

The sill, that's right... I was thinking about the floor structure.

Then there are metal sills, if I remember correctly. Good durability, doesn't mold.

 

[Milkshaken]

No problem with Treated wood and the rubber seal as a moisture barrier.... Personally, I don't want to use plain wood in a sill, but treated, of course with paper or as I said the rubber seal.... The rubber is also moldable....

 

[perra i skogen]

I read a month ago on a great site (which I've now lost ) that you should always build with pressure-treated sill. But in all the constructions I've seen and done myself, it has always been untreated wood. I think it's up to the builder to decide what he wants to use.

 

[Bogeymannen]

There seem to be mixed opinions about this, but after consulting Anticimex, I am certain about how I want it. No treated wood in residential buildings was their comment. It can start to smell!

 

[Hemmakatten]

We have pressure-treated sill plate (with sill gasket underneath) in our newly built stick-built house. It was specified in the construction drawings and the carpenter agreed.