Hey guys,

I'm a long time forum troller, first time poster, so first off I'd like to say thanks for all the help I have gotten from these forums in the past...Thanks!

Now on to business.. I'm going to be moving in to my brother's house in Calgary, alberta in a month, and will be turning the unfinished basement into my living space. One of my first concerns will be getting the floor done. So my first question is: Should I even bother with a subfloor? The basement is dry and the area has no issues with flooding and no apparent water leakage through the floor or walls. The only real reason would be to help keep the floors a bit warmer, especially since he plans to cover it in laminate and tile.

Assuming the subfloor is a good idea (I think it likely is) and we don't really feel like investing the many thousands of dollars in a radiant floor heating system (Unless you guys can tell me how to do it relatively inexpensively). I have a few question...actually lots of questions...

What is the recommended type of subfloor for me? There are so many options out there (and I'm not overly keen on the dricore or similar type tile products) and I wonder what is the best bang fro my buck as well as the most sound design.?

Some people say put poly down as a vapor barrier directly on top of the concrete, others say that's a bad idea because it needs to breathe. Some say to run poly up the walls a bit, some say to just cover the floor. Which is right?

If I were to do a subfloor made of 2x4 sleepers with 3/4 plywood or osb on top, does it need to be nailed/screwed/attached to the floor? If so, it seems like that would interfere with expansion/contraction of the wood? As a side question, are pressure treated 2x4's actually going to last as sleepers if a small amount of water gets in, or will they just mold anyways? I do see there is some mold/mildew/water resistant 2x4's out there which may be an option also?

How high can I go with the subfloor before I will have to adjust the stairs and doorways to compensate? (in regards to code mostly, more worried about the inspector than my own personal preference...I'm pretty short)

Is it normal practice to build the interior walls on top of the subfloor and just attach them to the joists above, without anchoring to the cement (again a little concerned about expansion and contraction of the subfloor material if I have several hundred tapcons put through it). The exterior walls up against the foundation are already framed.

When it comes to the bathroom, are shower/tub pans generally just installed over the concrete, or do they usually sit on top of the subfloor as well? I'm assuming the toilet will definitely be on top of the subfloor.

And finally, if you have any general advice or tips that might make my life easier I would certainly appreciate it. This will be my first full basement reno so I'm sure I'll be back to these forums for more great advice, and hopefully I can find a few things to lend any expertise I have towards as well.

Thanks again.

 

Laminate would be my last choice in flooring, especially in a basement. I would opt for click lock prefinished engineered flooring atop a recommended underlayment. I like using something like this as it allows an air gap between the concrete and the flooring. Roberts, AirGuard 100 sq. ft. Premium 3-in-1 Underlayment, 70-105 at The Home Depot - Tablet I would not bother building a subflooring system unless you had a severely uneven slab. Build your walls insulating them, finishing them, then install your flooring.

 

Thanks for the quick reply!

My thought behind building a subfloor wasn't so much to deal with an uneven floor, as I think this one is pretty flat, but moreso to help keep the floor feeling a little bit warmer. Up here in Calgary the winters get pretty cold and you can definitely feel it in the floors! Do you think that underlay you recommended would make a significant difference in keeping the floor warmer?

I will definitely look into some engineered flooring. I had been under the impression from the flooring places I'd checked out that laminate was perfectly fine for basement application, but as I look around here a bit more I see that a lot of people have issues. The vinyl stuff also doesn't seem to be that much more expensive so I think I will look at that option as well. Does the engineered hardwood hold up ok against minor spills and things like that? (A 6 year old will also have her play space down there as well)

Luckily all the exterior walls are already framed and insulated with vapor barrier up. All I have to do is run the electrical and then slap some drywall up to finish that portion of it.

 

No, the underlayment would have no affect on the floor temperature. Laminate will never be anything more than MDF with a picture of wood on it and aluminum oxide for a finish. It will clack under foot. Engineered flooring is actually wood and will withstand moisture and small spills much better than laminate. Hang in here as some of the others may have differing views on building a subfloor for your area. Here in the Southern US, we would not have such extremes, so I have no experience in that.

 

Ok, thanks for the info!

Hopefully some cold climate DIYers will chime in with any advice they have...