Peer & Beam Tile Flooring

I would like to chat with William Mear from Smallville, Texas. Please email me at "calvinbourgeois@yahoo.com". I am planning to build a peer and beam home in Schulenburg, Texas. The pad has been leveled and compacted. The soil is hard and test shows need for standard size footings and I would appriciate some advice on the subject of tile floors. Thanks Calvin

And you are willing to take advice from Mears because?

Haven't seen him around in a long time. Chances are he is no longer in the flooring business.

The only thing I know about Mear is that he had a tile business and in one forum he said that everyone in his little town (Smithville,Tx.) has peer & beam homes. My building site is near there. I was told yesterday by a tile salesmaan in Houston that a peer & beam construction would not support ceramic tiles. I think he is wrong and in speaking to a engineer who calculates the loads for the 16" floor joints I think I will use, he says it will support the 22lb. Dead load created by 1 1/4" t&g plywood sub-floor, 1/2" backer board and a ceramic tile. I will except advice from anyone. Thank you, Calvin

Live-load dead-load calculations are not necessarily the same as deflection criterias. Of course the structure will support the weight of the load, that's a given.

Have this "engineer" tell you what the "deflection" will be between the beams. Beams 48" on center are problematic (when it comes to tile installations) and the tile salesman may be correct. Living-in and selling-tile-in this area the tile salesman may have expert knowledge the brainiac engineer wouldn't even consider on a routine basis. We see this all the time.

Last fall I had an engineer for a truss manufacturer tell me that in his 16 years of designing floor trusses for residential applications he had never had anyone ask him for the deflection criteria of a floor until I came along with a travertine install and needed the information.

[Edited by Bud Cline on Wed, Jun 3, 2009 at 3:18 pm CST]

The floor truss engineer said he has designed my truss with a deflection ratio of 1" per 480" (40ft) and these truss span 17ft with his recommendation of 24" spacing. I am considering 16" spacing with 1 1/4" t&g plywood and 1/2" backer. Do you feel (2) x 5/8" plywood is stiffer than (1) x 1 1/4" sheets and does screwing them instead of nailing have any advantage? What about glue between the plywood and the 1/2" backer?

Can you comment on this statement that was a recommendation to have a good tile installation: "Use a latex modified thinset mixed with a flexible additive like laticrete and a 1/2"x1/2" saltillo trowel." Thanks Calvin

God help us!

I'm thinking the 1" per 480" you refer to is actually a deflection of 1/480 or (L/480). I'm also thinking 12" (typical) joists spanning 17 feet and 24" on center ain't gonna cut it. That will bring you in around L/300.

If you use 16" joists on 16" centers spanning 17' you will be plenty stout.

Do you feel (2) x 5/8" plywood is stiffer than (1) x 1 1/4" sheets

Stiffer isn't the only thing you are after in this case. The use of two sheets will afford you some needed additional lateral slip in the structure. Glue and screw the first layer to the joists. Don't glue the second layer at all and don't screw the second layer to the floor joists, screw it to the first layer purposely missing the joists. Lap all seams.

THEN install the tile backer board in a fresh mix of thinset and use fasteners as directed by the maker of the board. Use a 1/4" by 1/4" trowel, no more no less.

Can you comment on this statement that was a recommendation to have a good tile installation---yada yada.

DO NOT use an additive with modified thinset. That's what modified thinset is already. All the necessary additives are already in the bag. Dreaming up your own concoctions can wreck the intended chemistry of the product. Screwin' with it is some very bad advice you have gotten from someone.

What size/type tile are you using? Don't know if you said already but I ain't gonna go back and read all that stuff again.

[Edited by Bud Cline on Wed, Jun 3, 2009 at 9:17 pm CST]

Mr. Cline, I am considering 12'x12" or 13"x13" but have looked at larger. Which tile size is more acceptable to moving or cracking on a peer and beam floor?

Doesn't matter the size, larger tile will crack sooner, but if mosaics are used, doubt any will ever crack, but then all the grout will crack and chip up, either way it will fail if the floor doesn't meet specs for tile.

12 or 13" won't make a difference.

"Use a latex modified thinset mixed with a flexible additive like Laticrete and a 1/2"x1/2" saltillo trowel."

I am considering 12'x12" or 13"x13" but have looked at larger

A trowel 1/2" X 1/2" is way too big for those tiles. Where the heck are you getting this information? Never heard that trowel called a saltillo trowel but I can see why it would be,

Hey don't forget about the tile salesman that is recommending against this installation. I still side with him.