I have a customer who wants an elevated deck over a livingspace. Ideally the deck surface will be masonry – stone/tile/brick. Does anyone have experience with a reliable way to achieve this?
Discussion Forum
Discussion Forum
Up Next
Video Shorts
Featured Story
Dangerous electrical work and widespread misconceptions cause fires, deaths, and $1.5 billion in property damage annually.
Highlights
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Fine Homebuilding Magazine
Fine Home Building
Follow
-
Fine Homebuilding
Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.
Start Free Trial Now -
GBA Prime
Get instant access to the latest developments in green building, research, and reports from the field.
Start Free Trial Now
Replies
Let's prequalify this answer
Does the owner have more money then brains? if not, he can't aford what he wants.
Welcome to the
Taunton University of Knowledge FHB Campus at Breaktime.
where ...
Excellence is its own reward!
He does have money...and brains. He will expect a product that is aesthetically pleasing and functional - no water leaks below. Do you think that is an unrealistic expectation?
It's very, very difficult to detail properly. I'll take every opportunity I can to avoid designing one into a house (he says after designing one into his own house!).
Hi Cloud Hidden, gdcarpenter here, in Wesport, CT and missing NC already. At least the wine survived the move and is ensconsed in our latest basement wine cellar. Ever up this way give me a heads up.Let's not confuse the issue with facts!
Hi Garfield, that's quite a move! Work? Family?
I do this basic job at least once a year. I use EPDM as my membrane. The big cost and detail difference will be that he wants masonry type top surface deal. That means beefier joist framing underneath, and since the masonry is weight not watertight, a drainage plane has to be designed into the top. This takes up thicker dimensioning. if you are in an area where =freezing happens, things get even trickier. Frost can ruin it the first season if any wter is alllowed to become trapped in the system.The only times I have worked with a system like this were on university campuses rather than private residences. The vast cost/value difference as percieved by HOs really makes it difficult to design right.short cut would be to find 18" 2" thick tiles and laythem in on a sleepr grid without making it a masonry set in mortar.I gotta get off to the job now. Later...
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Thanks,Piffin. I have something like that in mind - 2" tiles(concrete/slate)over Duradek - although the EPDM might be cheaper. Seems to me I would need a cushioning/leveling medium under them like sand or granite dust. With frost heaving a concern, that medium would need to drain without washing away. Maybe a perforated border with a filter fabric to keep the sand from washing away. Isn't there a commercial system that uses a specific tile with elevating corner spacers that allow free flowing drainage under?
maybe something standard out there, but I don't know what it is. Keep the thread bumped up and somebody else may get to see it over the weekend
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Look at pedestal-mounted paver systems- you can get them with concrete, stone, or granite pavers. The pedestals create the drainage plane underneath for the water to get out. You'll also need a very high quality waterproofing membrane- if it was my house, I'd want an epoxy waterproofing system like Kemper or American Hydrotech- not just an EPDM system (too many flashing details, etc, that have to be perfect).
As already said, you'll also have to take into account the weight of the pavers and beef up the structure below accordingly.
Bob
One of the design challenges is the elevations. You have beefed up framing, waterproofing layers, pedestals, pavers, plus it's a good idea to keep the deck lower than the interior floor...that's a lot of thickness to account for when setting ceiling heights, stairs, etc. It affects the room that the porch is over, as well as requires some sort of transition to the other rooms. All in all, a labor and brain intensive undertaking.
plus it's a good idea to keep the deck lower than the interior floor...
I would like to double up on this key point. It's not just a good idea, it's absolutely essential that the membrane surface be lower than the interior living space.
In some designs, ponding water can occur on these decks and having the interior space at the same level would be disastrous.
In other designs, we have seen the membrane surface down about 3" from the floor with a deck on sleepers bringing the outside deck surface again, level with the interior floor. This too should be avoided. Wind blown snow will pile up against doors and leak to the interior during melting.
A full 7" step down onto a deck surface would be ideal.
carpenter in transition
NOt just snow. I know of one where the wind comes directly at it & in a heavy rain with big winds it will push the water up the wall.
Here's the system I have seen used to support the pavers:
http://www.bisonus.com/index.asp?pid=5
No mortar or grout, easy to remove, plenty of drainage area below. The installs I have seen had PVC membranes with drains, like a giant shower pan.
davidmeiland, Thanks for the link. I really like that system, but I think the extra load and elevation considerations will drive me toward something like the DuraDek or EPDM with PT sleepers and removable panels
PT sleepers supporting removable panels of what material?
I like western red cedar for the decking
I thought we were talking masonry. I've done one or two wood decks with sleepers over the roof and really don't like laying all that wood on the membrane. With the pedestal system you basically go out there in your slippers, set up the pedestals on a grid and then start having someone hand you pavers, which just sit on the pedestals.
When did you change from masonry to wood? Did I miss a post earlier or did my/our advice turn your customer around?
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
That was quickl! all I had to do was scroll down;/)
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
dave
what type of stone product are you laying with these ? is it gauged material ?
does it have square corners ? what stone thickness ?
carpenter in transition
Concrete pavers, square with square edges.
Got any links to pedestal/paver systems?
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Think of it as an outdoor shower pan. We do it in the house all the time & make it work, so why not outside......
Brick and Stone would be tough because of the weight...
Tile on the other hand can go directly overtop Ditra. In the Schluter installation guide they detail your situation.
Thank-you DanteO. I have gone to the Schluter website. Their product looks very promising
i'm with Piffin and Cloud in trying to talk you out of this.
my biggest concern: if after the membrane is installed and then the stone mason goes through the process of installing stone and its associated bedding, you get a leak or two after a couple of months, who is going to pay to rip all of the stone out to find the leak ?
and finding the leak could be quite difficult. jobs like this can bankrupt builders.
we did a deck just like this about 2 years ago. it was to replace the one that was installed when the house was built about 5 years before. that one leaked. the deck had a structural steel frame, corrugated decking with poured concrete.
our replacement cost a bloody fortune.
just down the street another homeowner had a similar deck but with an open area beneath. the structural steel frame beneath that one was rusted badly from all of the water leaking through the bluestone and concrete slab. ( it had a membrane which had failed )
i like the idea of this but prefer that it is done with EPDM with a wood decking system that is designed with removable panels that allow cleaning of loose debris from between the sleepers.
that way if a leak does occur, the access to the membrane won't cause you a month's worth of sleepless nights.
carpenter in transition
You might have a look at
http://www.xypex.com
Any cracks, though, would be fatal to the watertightness, so you'd still need the EPDM. Maybe as a belt and suspenders approach ....?
-- J.S.
Duradek is what I use. http://www.duradek.com it has to be installed by a dealer but it looks good & works.
I've read about that, but never speced it. Any more to offer on your experience with it? Pricey if I recall, yes? Did they detail the edges good? In my experience, that's the tough part...easy to cover the field, but hard to waterproof the building connection and free edge.
Robrehm,I have talked to the local DuraDek contractor, and will strongly guide my customer that way
That is the membrane , but you still need a plan to deal with the masonry and a way to bleeed the water out of it. ANY roof system that retains water will fail, so the design and installation has to make sure that no water can remain contained
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
duradek looks a lot like a product made by Andek that I saw a few years ago. it was a new home with a second floor deck with a thin rubbery coating applied directly to the plywood deck. the builder had their carpenters do the install. it was their first ever.
Andek sent two reps to investigate the failure of the system. they explained the install process which involved a primer and then the liquid membrane install with paint rollers and brushes. An fine aggregate had been broadcast into the topcoat.
To Andek's credit, the installers were rookies without a clue.
Unfortunately, nails were popping out of the sheathing and through the membrane which wasn't thick enough, but I don't think the thickness would have mattered. foot traffic would have quickly worn the product away.
The other thing that scared me were the sidewall flashings with that particular application.
The Andek reps claim their products are covering thousands of these decks in Florida and many with stone pavers on them. Much of what I have seen in Florida has been cast in place concrete construction which is well suited to this type of deck setup.
carpenter in transition
That's one of the reasons you can't istall duraadek yourself. It has to be installed by dealer. No liquid membrane either. It comes in rolls & is heavy, lots of fun to carry up 3 floors.
If masonry is wanted - look at http://www.grailcoat.com ~ $4 s.f., but very permanent and waterproof.
are you in a frost-free area?
Brian, Grail coat site looks interesting. Have you used it. Can you walk on it? What kind of substrate is required?
I have a sample of it here in my desk drawer - call them & they'll send one. Its very tough stuff - I called one of their contracters & (grain of salt) he loved the stuff.
You put down lath, then 3 separate coats of the material. It is flexible and incredibly strong, like leather concrete, if that makes sense. I'll be doing my deck with it soon.
Treat every person you meet like you will know them the rest of your life - you just might!
Look at this. I'm doing one right now for my kid. We'll end up with a form of trowled appearing colored concrete 3/4" thick over 3/4" exterior ply.
http://www.miracote.com/index.php?href=productdetail&id=28
Then click on "Download Literature" in the left menu.
Then click on the Miraflex II evaluation report. It's 4 pages long and briefly summarizes 5 different methods, depending upon your application.
Ours will be replacing a wooden deck and providing dry storage space under for lawn equipment.
My poker buddy has this system in his new house. A patio made of thin, flexible, epoxy -fortified cement coupled with stucco / plaster mesh and a few coats of waterproofing over a hot tub & such below.
Edited 7/16/2006 11:46 pm ET by peteshlagor
Thanks to everyone who has contributed to this discussion. I have increased my knowledge and resources for waterproof decks. I plan to give my customer the options of DuraDeck, or EPDM with a cedar deck floating over. Of the masonry choices, the pedestal mounted pavers with the freeflowing drainage under seemed the best, but the questions of weight, floor thickness, and cost are pushing me towards something simpler.