Slate floor too heavy for second floor kitchen?

[Scriptbunny]

I'm ripping out old laminate flooring in the kitchen of my 100-year old home and thinking of replacing it with slate. The issue is that slate is heavy and I am afraid that it might cause my floors to sag or settle over time. Right now my floor consists of my downstair neighbor's ceiling (3 psf), hardwood floor original to the home (3 psf), plywood (1 psf), cement boards (2 psf) and then laminate on top. The slate (6 psf) would be on top of all that, minus the laminate of course. Also possibly minus the plywood underlayment (tile guy is saying I should remove?) for a possible total of 14 psf dead load.

None of the contractors I have talked to have blinked an eye when I tell them I want slate floors but I am still worried. Will having that much dead load be an issue or am I just being paranoid?

[deborah]

Probably paranoid, as things 100 years ago tend to have a lot of extra tolerance. However, you might have a noise problem (and a complaining neighbour) especially if you leave the underlayment off.

[music lover]

6 psf is nothing. Think of how much a person or a fridge weighs.

The biggest concern I see is that the tile layer want you to remove some of the plywood. Plywood thickens the floor and makes it stiffer, which is exactly what you want with a tile floor. If the floor is not stiff enough, then the tiles and/or grout lines will eventually crack.

[Scriptbunny]

I guess my biggest concern is that I remember reading that residential structures can handle 10 psf dead load and 40 psf live. I'm afraid my dead load is going to be kind of high with the two heavy layers of flooring, all that even before big appliances. I'm not worried that it'll fall through the floor or anything, but that the weight over time could turn into a structural issue.

Also anyone know why my tiler would suggest removing plywood layer?

[Greg]

More important is what are the size, spacing and span of the floor/ceiling joists?

[waffle]

More important is what are the size, spacing and span of the floor/ceiling joists?

+1

People say that houses 100 years ago were built extremely solid. That can be the case, but not always. Check what is supporting the floor. I've seen really old houses that are more solid than brand new houses, but the house I grew up in was built in the early 1900's and we just tore it down when we moved out it was so poorly built.

[Scriptbunny]

Joist measurements:
* Width 2"
* Height 9"
* Spacing 16"
* Span 11.5'

According to an online calculator I found I should be good on deflection (L/770 vs L/720 needed for natural stone). But I don't know how to figure out joist strength / max dead and live loads.

[Bob W]

Joist measurements:
* Width 2"
* Height 9"
* Spacing 16"
* Span 11.5'

According to an online calculator I found I should be good on deflection (L/770 vs L/720 needed for natural stone). But I don't know how to figure out joist strength / max dead and live loads.

Modern calculators probably won't help as I'm guessing your joists are hardwood,  possibly oak.   I'm thinking an oak floor with a 16"  11.5 span is a pretty freaking solid floor.

I'm also curious why you don't restore the hardwood or alternatively go with a much cheaper Tile.   Even some of the new laminates are pretty sweet looking and you could do a lick and stick DIY for pretty cheap.  That is what I would do.    I think you project sounds uber expensive and the rewards are slim.    Is it a keeping up with the Jones thing or do you have a special connection to slate? 

[Scriptbunny]

I have been told my floors are fir and, from my completely newbish eye, the hardwood joists look to be of the same material.

I am not refinishing the hardwood because of two reasons. 1. I had a chimney and nlb wall removed which has left gaps in the hardwood. I have been told buying replacent wood to match mine and refinishing would be similar in cost to retiling (though I did not get an exact # to compare). And 2. I use the kitchen a lot and I do spill things. I am afraid hardwood won't stand up to the wear and tear.

On slate v laminate, I just really like the feel of cool stone especially in the hot summertime. Also I have not yet met a laminate I like but would certainly take suggestions.

[paddedhat]

When you are referring to slate, I hope you are talking about getting a high quality, fairly expensive, precisely cut product from a reliable flooring supplier? The reason I ask is that all the big box stores in my area sell a horrendous, extremely low quality slate that they import from India. The stuff looks beautiful, and I have used it extensively on fireplace surrounds, but it would be a disaster on a floor. The stuff is typically radically out of square, with extreme thickness variation ( literally, I have pulled tiles out of the box that vary from 1/8" to 5/8" thick) , and it can flake easily.

I have done very little real slate on floors, and when I did it was about $6-7 sq. ft. for material. I have done at least a dozen kitchen floors with a high grade porcelain tile that looked exactly like slate. This stuff was under $2 sq. ft. looks great, is rated for commercial use, and easy to use. No matter what you decide, take a look at the bright orange "Ditra" underlayment. It's the only thing I would ever use. Good luck on the project.

[ShoulderThingThatGoesUp]

Depending where you are, you might be able to buy it from a quarry. I know a guy here who replaces slates on roofs sometimes, and buys it directly from the quarries because they're only half an hour away or so.

[lakemom]

I have been told my floors are fir and, from my completely newbish eye, the hardwood joists look to be of the same material.

I am not refinishing the hardwood because of two reasons. 1. I had a chimney and nlb wall removed which has left gaps in the hardwood. I have been told buying replacent wood to match mine and refinishing would be similar in cost to retiling (though I did not get an exact # to compare). And 2. I use the kitchen a lot and I do spill things. I am afraid hardwood won't stand up to the wear and tear.

On slate v laminate, I just really like the feel of cool stone especially in the hot summertime. Also I have not yet met a laminate I like but would certainly take suggestions.

Your floors are 100 years old and you think you're tougher than they are.  And/or tougher than any previous owner?  Seriously, properly done solid hardwood (or heart pine) floors will last forever even in a kitchen.  My brother's house is almost 100 years old with heart pine throughout INCLUDING the kitchen and those floors are indestructible.  My parents raised 7 kids in that house (before they sold it to bro 5 years ago) and believe me we spilled on the kitchen and dining room floors, had sinks and freezers flood on it and left windows open in storms regularly and those 100 year old floors are still going strong.  We just have an oiled finish on them (no varnish in the years my family has owned it and I think its only been oiled/waxed in all that time) and waxed 1X per year and they were good to go.  Mind you they don't look like brand new floors they look like well taken care of 100 year old floors.

[Bob W]

http://www.armstrong.com/flooring/laminate/slate-pebble-dust-stone-ceramic-tile-L6570/floor-118462.asp

I'm thinking the price differential between a Laminate like this done DYI and high dollar slate installed by a real pro will be something like $25 a square foot.   Not sure how big your space is  but that is a significant difference.

Consider also that people generally like to change up things every 4-7 years,  so humans being humans you may want to redo this again in 5 years. 

Also confused about liking the cold feel of it?  Are you in the deep south?  Most folks I used to do tile for wanted me to install electric heat under the tile to keep them warm.  Funny how people's preferences differ. 

Just my cheap ass mustachian side talking.

[Scriptbunny]

When you are referring to slate, I hope you are talking about getting a high quality, fairly expensive, precisely cut product from a reliable flooring supplier? The reason I ask is that all the big box stores in my area sell a horrendous, extremely low quality slate that they import from India. The stuff looks beautiful, and I have used it extensively on fireplace surrounds, but it would be a disaster on a floor. The stuff is typically radically out of square, with extreme thickness variation ( literally, I have pulled tiles out of the box that vary from 1/8" to 5/8" thick) , and it can flake easily.

I have done very little real slate on floors, and when I did it was about $6-7 sq. ft. for material. I have done at least a dozen kitchen floors with a high grade porcelain tile that looked exactly like slate. This stuff was under $2 sq. ft. looks great, is rated for commercial use, and easy to use. No matter what you decide, take a look at the bright orange "Ditra" underlayment. It's the only thing I would ever use. Good luck on the project.

I was planning on using MS International gauged slate, 12x24 pieces. I read it was Brazilian slate, it is theoretically well reviewed and is super cheap at $3/sqft, though I definitely saw a review noting non uniform thickness between orders.

[Scriptbunny]

I have been told my floors are fir and, from my completely newbish eye, the hardwood joists look to be of the same material.

I am not refinishing the hardwood because of two reasons. 1. I had a chimney and nlb wall removed which has left gaps in the hardwood. I have been told buying replacent wood to match mine and refinishing would be similar in cost to retiling (though I did not get an exact # to compare). And 2. I use the kitchen a lot and I do spill things. I am afraid hardwood won't stand up to the wear and tear.

On slate v laminate, I just really like the feel of cool stone especially in the hot summertime. Also I have not yet met a laminate I like but would certainly take suggestions.

Your floors are 100 years old and you think you're tougher than they are.  And/or tougher than any previous owner?  Seriously, properly done solid hardwood (or heart pine) floors will last forever even in a kitchen.  My brother's house is almost 100 years old with heart pine throughout INCLUDING the kitchen and those floors are indestructible.  My parents raised 7 kids in that house (before they sold it to bro 5 years ago) and believe me we spilled on the kitchen and dining room floors, had sinks and freezers flood on it and left windows open in storms regularly and those 100 year old floors are still going strong.  We just have an oiled finish on them (no varnish in the years my family has owned it and I think its only been oiled/waxed in all that time) and waxed 1X per year and they were good to go.  Mind you they don't look like brand new floors they look like well taken care of 100 year old floors.

Well tbh I don't know the condition of the wood since it has been tucked under the laminate. It really is that plus the fact I would have to buy a bunch of wood to patch the torn up regions. And while I don't think I'm tougher than my house I certainly am prone to pushing things to their limits. I like to think of myself as a very good user tester of life (rather than what I really am which is a klutz).

[Scriptbunny]

http://www.armstrong.com/flooring/laminate/slate-pebble-dust-stone-ceramic-tile-L6570/floor-118462.asp

I'm thinking the price differential between a Laminate like this done DYI and high dollar slate installed by a real pro will be something like $25 a square foot.   Not sure how big your space is  but that is a significant difference.

Consider also that people generally like to change up things every 4-7 years,  so humans being humans you may want to redo this again in 5 years. 

Also confused about liking the cold feel of it?  Are you in the deep south?  Most folks I used to do tile for wanted me to install electric heat under the tile to keep them warm.  Funny how people's preferences differ. 

Just my cheap ass mustachian side talking.

Thanks for the suggestion!

I am from the southwest, grew up in a home with lots of natural stone. I'm sure the slate will freeze off my Northeasterner toes, but nostalgia...

[zinethstache]

Bob W. I was thinking the same. I put in tile our current home and its COOOOLD... Im in the PNW where it is often cold. In hindsight it would have been lovely to have a heat pad put in under it. Because it is in the kitchen I can't really use rugs efficiently. The bathroom tile was immediately covered by a runner rug so it works well and looks great. This is my first tile experience as an installer and user. Lesson learned!
 
I am betting this is in a warm region where tile would be most welcome.