engineer wood vs solid wood (custom home, live in, cost)

[jobert]

If you install laminate yourself, make sure you do the following:

1. run the planks perpendicular to the major window/outside light source of the room.
(if installed parallel, the imperfections will magnify)

2. start laying the planks on the wall with the most door frames if possible - it's easier to slide that first plank underneath the door frame instead of having to cut notches in the last plank to make them fit - you'll see what I mean when you get to the opposite wall.

3. If there is a concrete slab that shows noticable deflection, apply a self-leveling compound to make the floor truly flat, or you'll notice the floor will "give" when you step in these depressions, not to mention the air pocket underneath will exacerbate the noise from foot traffic.

I learned this all the hard way.

[Austin97]

Originally Posted by jobert

I am not sure I follow the logic. The slab in the interior of the house will be temperate year-round as you are running HVAC, and the other side of the slab is earth, which is temperate by nature. This is why you do need expansion joints on a slab . Even if the wood expands and contracts, it will expand and contract lockstep with the adjacent materials and substrate. Any movement difference would be concealed at the perimeter by the overlap of your base or quarter-round moulding. You may see buckling of the caulk if anything was to happen, but that is still unlikely.

concrete can hold a lot of moisture and can absorb moisture from the outside. That moisture can be absorbed into the wood causing it to expand. At the edge of the floor you are right it doesnt matter, but between slats you can get buckling. Our installer has said they have even seen a wood floor on concrete literally explode from the pressure due to improper installation.

Wood definitely expands more than concrete and more with the grain than against the grain. The thicker the wood, the more it expands in all directions. One installer that posted that said he wouldnt even put solid wood onto a slab - most installers we talked to said the same.

[BentBow]

Originally Posted by jobert

If you install laminate yourself, make sure you do the following:

1. run the planks perpendicular to the major window/outside light source of the room.
(if installed parallel, the imperfections will magnify)

2. start laying the planks on the wall with the most door frames if possible - it's easier to slide that first plank underneath the door frame instead of having to cut notches in the last plank to make them fit - you'll see what I mean when you get to the opposite wall.

3. If there is a concrete slab that shows noticable deflection, apply a self-leveling compound to make the floor truly flat, or you'll notice the floor will "give" when you step in these depressions, not to mention the air pocket underneath will exacerbate the noise from foot traffic.

I learned this all the hard way.

1.) Actually there are several rules to go by. Some contradict the others..
Running the length of the planks into the light, but if that is the short way across the room, it will make the room look smaller. Run the flooring across perpendicular to the floor joist. But in all reality, you can throw all those rules out the window, and do what you wish with the direction, even doing a 45º or less angle installation.

2.) Yes, this is the easiest to do. Popping a line out and working back to the wall with the doorjambs with you cutting and marking, to keep things square. If you do end with a wall and a doorway, Put an end joint in the doorway to get the planks under the undercut doorjambs.

3.) Self leveling compound is not a spot filler! It is not very DIY friendly, as it is best to use a mixing pump to apply it in the amount needed to make a good cap. I would use a Feather Finish portland patching compound, like ARDEX, Chemrex and Mapei make, using a screed to drag the mud across the low spots. But before you fill you must grind the high spots. Use a 8 ft. straight edge, pipe or a string pulled tight, to map the high's and low's.

It is not the noise your worried about with an out of spec substrate. It actually voids all warranties implied to the floating floor, by the manufacturer. The flexing destroys the floor, causing T&G cracking, edge chipping and joint separation.


Over concrete and a floating floor, a moisture barrier is required. I personally don't trust the 2-n-1 or 3-n-1 underlayments that say they are also the moisture barrier. I always use a 6-mil plastic poly overlapped and the seams taped with clear packing tape that has a high perm rating, then the 2-n-1 cushion.

If your directly bonding to the concrete, 3 calcium chloride test are set, to measure the concrete moisture vapor emissions(vapors cannot be seen) A Tramex Concrete Moisture Encounter Meter is accepted by many manufacturers now, and the ANSI 2071 internal concrete humidity in-stu is being accepted more and more also, and I feel is the better test for concrete moisture.

As an NWFA Certified Investigator, I have many many pictures of wood floors that have exploded off the concrete, in mountains. One the wood floors were put in before the cabinets and the cabinets installed on top of the 5" wide hickorywood floors. The floor buckled in many places before the home was finished being built and closed on, and it made firewood out of the cabinets and busted the granite countertops, that were one of a kind.

[Dennuchi46]

try cutting the door casing instead of the floor Then slide the flooring under the casing. It makes a better looking finish

[BentBow]

Originally Posted by jobert

I am not sure I follow the logic. The slab in the interior of the house will be temperate year-round as you are running HVAC, and the other side of the slab is earth, which is temperate by nature. This is why you do need expansion joints on a slab . Even if the wood expands and contracts, it will expand and contract lockstep with the adjacent materials and substrate. Any movement difference would be concealed at the perimeter by the overlap of your base or quarter-round moulding. You may see buckling of the caulk if anything was to happen, but that is still unlikely.

The temperature of the slab, along exterior walls can be hotter and colder than the interior temperature.
Not everyone runs their HVAC year around non-stop. My parents don't. They open windows and run the fans all of the spring and going into the summers, especially in the mornings, when humidity is at its highest of the day. This can easily pop a dew point on the cooler concrete. Condensation, means surface moisture.
Engineered can handle these brief periods of high moisture, where a solid will react and expand almost immediately. Wood absorbs moisture in the cells, faster than it will release the moisture given the same %, + or - the starting moisture content.

Expansion joints in concrete pours, is to control concretes ability to shrink, as it dehydrates. If no control joints are engineered into the slab, the concrete will crack massively, as you see in residential construction, where no control joints are designed into the fast paced cut, every corner construction, that is slapped up these days.

Ever see a slab expand and heave? NO, you haven't, have you!!!

[G Grasshopper]

With all this discussion of the disasters that happen with wood on a slab, I'm wondering if carpet is the way to go. How about cork and tile? Do they have similar expansion/moisture problems?

[BentBow]

Cork doesn't like moisture, either. Ceramic tiles are your best bet when moisture is involved, but then were are back to cracked concrete slabs.

[G Grasshopper]

So you are saying that when the slab cracks, the tile will crack with it? If you can prevent cracking of the slab with expansion joints, how do you prevent cracking of the tile above when the slab expands?

[BentBow]

Originally Posted by G Grasshopper

So you are saying that when the slab cracks, the tile will crack with it? If you can prevent cracking of the slab with expansion joints, how do you prevent cracking of the tile above when the slab expands?

Yes, it is documented fact, not just me saying, that tile set on concrete, will crack if the concrete under it cracks from shrinkage, not expansion. Expansion gaps are honored in the tile installation, with a flexible joint. Schluter has a nice profile.

It depends how bad the slab cracks, as to what you can do to prevent the tiles from cracking. small cracks can be addressed using an anti-fracture membrane, or and membrane like Schluter: Ditra(do a Google) Then there is the old tried and true mud bed, but you will be hard pressed to find someone that knows how to do a proper mud bed, as the new thinsets and CBU backer panels have made that art a thing of the past, even though it is a superior installation.

There is a big difference in the $2 a foot guy and the $8 a foot guy and it isn't just the price difference. One guy gives you the tail light warranty, and the other guy takes so much pride in his craft, that he will stand behind it, for as long as he is breathing.

[G Grasshopper]

Thanks, BentBow. I did do a Google, and learned a lot. I'm hoping to actually know some things when searching for a house. People do all kinds of things to their homes, and its difficult to know some times if they will hold up in the long run. I appreciate your expertise.