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    baradou's Avatar
    baradou Posts: 23, Reputation: 1
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    #1

    Jul 22, 2009, 06:55 AM
    raising a concrete floor by approximately 1",for tiling
    I have a concrete area size 9'*8'= 72sqft, in the basement and would like to raise it by about 1" (7/8") and then install ceramic (this area will be a bathroom), so it will be at the same level as the rest of the floor which I will be raising by 7/8" when I install the drycore panels over the concrete.
    I will install a floating laminated floor over the drycore panels.


    I have looked at SLC (EZ-Flow ), about 6-7 bags of 50LBs each, add some pea gravel so to reach about 1" of thickness.

    I also read that the other option would be to nail outside grade 1/2" plywood to the concrete floor and then glue another 1/2" plywood to get my 1".

    I also read that if I put sleepers on the floor with 1"* 3" *8' strips and then lay a 6mm vapor barrier and then nail the 5/8" plywood over the sleepers/vapor barrier,it would also be a solution.

    What would you guys recommend?
    Bljack's Avatar
    Bljack Posts: 245, Reputation: 28
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    #2

    Jul 22, 2009, 02:43 PM
    Quote Originally Posted by baradou View Post
    I have a concrete area size 9'*8'= 72sqft, in the basement and would like to raise it by about 1" (7/8") and then install ceramic (this area will be a bathroom), so it will be at the same level as the rest of the floor which I will be raising by 7/8" when I install the drycore panels over the concrete.
    I will install a floating laminated floor over the drycore panels.
    The dricore stuff is pretty cool. Save yourself from the headache of using those leveling shims by doing a real thorough check of the slab first. Give any high spots a quick grind down and any low spots a quick flash with a portland cement based floor patch. You only need the floor to be flat. Level is completely different and a lot more work. A block of wood, with a string wrapped around it, have someone hold it tight on one side of the floor, have another person with another equal sized block on the opposite side, pulling the string tight as they move along the wall. All your peaks and valleys will jump out at you.


    Quote Originally Posted by baradou View Post
    I have looked at SLC (EZ-Flow ), about 6-7 bags of 50LBs each, add some pea gravel so to reach about 1" of thickness.

    I also read that the other option would be to nail outside grade 1/2" plywood to the concrete floor and then glue another 1/2" plywood to get my 1".

    I also read that if I put sleepers on the floor with 1"* 3" *8' strips and then lay a 6mm vapor barrier and then nail the 5/8" plywood over the sleepers/vapor barrier,it would also be a solution.

    What would you guys recommend?
    SLC, especially with pea gravel mixed into it can quickly become quite a mess. If you must do it, make sure you have a large supply of water, have all your bags open and ready to mix, one person mixes, one pours and rakes, if you mark one or two buckets with a marker with the correct amount of water so you are not measuring it over and over again... the key to success with slc is speed.

    You will need the appropriate slc primer, which you should apply with a brush as they don't leave puddles of primer like a roller would and you will also need to use something to provide a 1/4" perimeter gap. If you have a trench around the basement for the sump pump, screw a 2x4 into the wall and use a piece of thin foam along side of it (thin like sill plate gasket foam), or if you don't have a sump pump trench, just use foam weather stripping around the pour. Fasten a dam at the bathroom entrance.

    The least expensive method would be to mud the room. Figure about 8 bags of sand mix and 2 bags of sand, mix it with only enough water to make it a packable sandcastle consistancy. Take some 3/4" pvc or rip some 2x4's into 1" wide pieces to use as screed guides. Lay your screed guides on the floor, spread a bit of runny thinset on the floor, pack your mud into the area between the screeds, beat it down tight to pack it really good, shave off any excess from the top by running a straight edge back and forth over the top of the mud, drag your screed guides down into the room further, pack the area where the screed guides were just removed, and keep going until the floor is done. It is the least expensive way to do it. Sand mix is 1 part porland, 3 parts sand, the mix you want is 4-5 parts sand, 1part portland, so cut your sandmix with some sand.

    Don't bother with any of the plywood to slab nonsense.
    davep5's Avatar
    davep5 Posts: 25, Reputation: 1
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    #3

    Jul 22, 2009, 03:38 PM
    they do make 2x2 ft square plywood with plastic feet on the underside of the plywood. Its used for flooring over concrete.(I don't know the name of it) Im sure you could get it at a home depot or Lowe's. Put a vapor barrier over the concrete, the 2x2 squares and then a concrete board screwed into the plywood top, with the concrete screws . Ant it will be ready for thinset and tile. When added up it should turn out to be 1''. It also depends on the thickness of tile you want too
    Bljack's Avatar
    Bljack Posts: 245, Reputation: 28
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    #4

    Jul 22, 2009, 04:03 PM
    Dave, the original poster is using Dricore which IS the 2' square panels of underlayment with the plastic feet. The original poster was already aware, and now you will be too, that Dri-core panels are not to be part of a ceramic floor assembly, ever. Also, you mentioned that he should screw cement board into the top and then he would be ready for thinset and tile? Even if the dricore could be used with tile, you are aware that every single cement board on the market must be set into a bed of thinset prior to securing it to the floor, right? There are no exceptions.
    baradou's Avatar
    baradou Posts: 23, Reputation: 1
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    #5

    Jul 23, 2009, 06:21 AM
    Thanks Bljack for all the clarifications and guide.

    1- Is there a reason for adding 2 additional bags of sand to the 8 bags. I visited the local home depot and they carry the Quikcrete sand/topping mix to which I can add only water to get the right texture of mud, I think some people call it dry mix.

    2- When you mention the thinset, is it so the mud bonds better to the surface. Quickrete also carries the bonding agent , is this preferable or a regular modified thinset would do?

    3- Now on the perimeter of the 72sqft area, do I still have to install the thin foam you were mentioning if I decide to go with the SLC approach, which I am not, so the mud does not get in contact with the sill plates holding my walls on the perimeter?

    4- Given that I will have to use the 8 bags of topping mix and 2 bags of sand, I was planning on buying a regular plastic flat bin (the one they use for under bed storage) to mix 1 or 2 bags at a time and work with smaller areas, using the 1" pieces from 2*4 you mentioned to screed , is this ok to do?

    5- Is it ok if the mud get in contact with the drywall around the perimeter or is it preferable that I pour my mud before putting the drywall?

    6- I have some extra galvanized chicken wire, should I use it/lay it before mudding or I don't need it given that I will only be reaching a thickness of 7/8"-1".
    baradou's Avatar
    baradou Posts: 23, Reputation: 1
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    #6

    Jul 27, 2009, 05:26 PM

    I am getting around to start this project in the next 2 days. One word of caution though for the adventurous out there,don't be tempted to lift those 60lbs bags of sand or sand topping mix by yourself,especially going down a flight a stairs to a basement as you can injure your back. Ask for help, I did not and ended up busting my back and slowly recovering.

    If you guys have any tips, it would very much be appreciated.
    baradou's Avatar
    baradou Posts: 23, Reputation: 1
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    #7

    Aug 9, 2009, 07:21 AM

    It is been 8 days since I got done with the resurfacing/raising the floor by 1". Given that it took me 2 days to apply the mud on the 72 sqft surface (could not finished it in one day). Today I noticed that there is a crack btw the section where the previous day mud job meets with the next day. Also if I tap lightly on that section, I can hear a hollow sound.

    Don't know if I need to break the whole thing or just the section where they meet, break it down to reach the floor under that 1" and re-mud.

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