Joist stiffening/sistering with partition wall in the way
- Thread starter Kodi Crescent
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Cheese
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So if you were sistering joists [member=28648]TooManytoys[/member], what would be your adhesive of choice?
Like [member=1146]Brice Burrell[/member], I've used PL 3x & PL 8x to sister in the past, but maybe Gorilla glue, epoxy or resorcinol would be a better choice?
As an interesting aside, PL 3x always seemed to cure hard while PL 400 or Liquid Nails always cured to a more rubbery texture and that's the reason I used neither of them for sistering duties.
Like [member=1146]Brice Burrell[/member], I've used PL 3x & PL 8x to sister in the past, but maybe Gorilla glue, epoxy or resorcinol would be a better choice?
As an interesting aside, PL 3x always seemed to cure hard while PL 400 or Liquid Nails always cured to a more rubbery texture and that's the reason I used neither of them for sistering duties.
TooManytoys
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Just to clarify, with sistering a like sized member I'm not sure it's important when trying to improve deflection.
Three years ago I started to look at adhesives because my fallback wood structural adhesive, resorcinol, was no longer on local lumberyard shelves. That's when I started emailing around and got discouraged. I have a BIL who restores wooden boats and taught at a museum and he switched over to epoxie. I was about to then I found out you could still get resorcinol from Aircraft Spruce trade named Cascophen. For the two projects I did that's what I used.
I've since learned that product from AS as well as some other sources of resorcinol have been hit or miss as far as working well. Resorcinol ingredients have a shelf life and some suppliers are selling outdated materials. Maybe as of today that has changed, but it leaves me in a quandary for a new project coming up soon, a raised ranch floor with large tiles, and the second story wall extends out 24". So the floor of this kitchen is reverse loaded by the roof load, the fulcrum being the first floor exterior wall.
Getting back to point, if I do build up the joists as I-beams for stiffness, the Cascophen shows it's still available or I might just go epoxy.
Three years ago I started to look at adhesives because my fallback wood structural adhesive, resorcinol, was no longer on local lumberyard shelves. That's when I started emailing around and got discouraged. I have a BIL who restores wooden boats and taught at a museum and he switched over to epoxie. I was about to then I found out you could still get resorcinol from Aircraft Spruce trade named Cascophen. For the two projects I did that's what I used.
I've since learned that product from AS as well as some other sources of resorcinol have been hit or miss as far as working well. Resorcinol ingredients have a shelf life and some suppliers are selling outdated materials. Maybe as of today that has changed, but it leaves me in a quandary for a new project coming up soon, a raised ranch floor with large tiles, and the second story wall extends out 24". So the floor of this kitchen is reverse loaded by the roof load, the fulcrum being the first floor exterior wall.
Getting back to point, if I do build up the joists as I-beams for stiffness, the Cascophen shows it's still available or I might just go epoxy.
Kodi Crescent
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It's been a bit since I've looked at this thread. Lot's of great discussion! I especially appreciate the table with the different reinforcement options.
Another option was to reduce the weight of the installation. I asked the tile contractor to use one of the newer foam systems, and he quoted me some options which seemed to be excessively priced. . So I'm going to do the prep work myself. I'd cancel the contract, but it is fairly penalty heavy even though he didn't start yet. (I'm going to start striking those clauses in the future). Doing the prep work will give me what I want at half the price of what he wants to install something similar.
There's a relatively new product out called the Durock Shower System. It's all foam, so I get rid of all the heavy substrates. It should remove 350+ lbs from the load. I believe the design of it acts as a decoupling membrane, so some of the cracking from lateral movement may be limited. I'm thinking about adding a 1/2" plywood to my 3/4" floor just to make things a bit stiffer on the floor portions.
I may insist on Ditra on the rest of the floor, especially since I'm doing all the shower prep.
Another option was to reduce the weight of the installation. I asked the tile contractor to use one of the newer foam systems, and he quoted me some options which seemed to be excessively priced. . So I'm going to do the prep work myself. I'd cancel the contract, but it is fairly penalty heavy even though he didn't start yet. (I'm going to start striking those clauses in the future). Doing the prep work will give me what I want at half the price of what he wants to install something similar.
There's a relatively new product out called the Durock Shower System. It's all foam, so I get rid of all the heavy substrates. It should remove 350+ lbs from the load. I believe the design of it acts as a decoupling membrane, so some of the cracking from lateral movement may be limited. I'm thinking about adding a 1/2" plywood to my 3/4" floor just to make things a bit stiffer on the floor portions.
I may insist on Ditra on the rest of the floor, especially since I'm doing all the shower prep.
Kodi - there's plenty of info out there about tiling systems.
The problem with all this joist talk in regards to tile is deflection. And while that is caused by weight and directly related to span - it's the weight of the tile itself and the setting material that causes the lion's share of the issues.
Your choice underlayment, be it, foam, or mud and liquid membrane, or a cast terazzo or acrylic showerpan is not causing a tipping point of your joists not passing muster. It the tile ! These new materials are just allowing for faster job cycle times with less of a skilled labor force. They are not magic pills that somehow allow one to suddenly have tile when their underlying structure won't support it. [sad]
The problem with all this joist talk in regards to tile is deflection. And while that is caused by weight and directly related to span - it's the weight of the tile itself and the setting material that causes the lion's share of the issues.
Your choice underlayment, be it, foam, or mud and liquid membrane, or a cast terazzo or acrylic showerpan is not causing a tipping point of your joists not passing muster. It the tile ! These new materials are just allowing for faster job cycle times with less of a skilled labor force. They are not magic pills that somehow allow one to suddenly have tile when their underlying structure won't support it. [sad]
Kodi Crescent
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I understand. Per the engineer's evaluation, my structure will support the work with the originally proposed materials (mud and cement board). In a follow up email the engineer told me that there would be an additional 1% deflection each year due to seasonal humidity changes. So that 10 or so years from now there may be sufficient additional deflection to cause tile cracking. I plan on being in this house long term and would like a bathroom that will last as long as my family stays here. It's this "additional seasonal deflection" that I'm concerned about.
I looked at what it would take to beef up the structure to lessen the deflection and sag for "additional surety, if desired" as the the engineer's letter states. I have utilities going through that area, and I'm kind of tired of doing drywall work. I don't want to cut my subfloor open to access from the top. It's a big hassle, and doesn't resolve the issue that led to this thread.
The tile contractor's proposed work eliminated the traditional pre slope bed that is supposed to go under the mud bed. Plumbers are now laying the vinyl membrane flat on the subfloor. The tile guys are laying the sloped mud bed down and then applying a waterproofing membrane to the sloped mud bed to prevent water intrusion into the bed. If that membrane fails, the shower pan will not work as the traditional design where water is "exchanged", as there is no pre slope to guide the water to the drain weep holes. The way around this issue is to use a bonded flange drain with a waterproofing membrane. But bonded flange drains are not allowed in this municipality for some reason.
If the tile guy wasn't going to put in the pre slope bed, I was going to. After making a test pre slope bed, I started to think about the weight of the materials and the effect on the structure.
Before I started this project, I wanted the newer foam products to be used instead of the traditional methods. The tile guy doesn't use the foam products, and he wasn't even going to do the traditional method as it was designed. I have a penalty heavy contract with him, so firing him isn't very feasible. I may look into canceling the contract anyhow (I learned a lesson about signing these one-sided penalty-heavy contracts. Education isn't always cheap).
After pricing out the foam stuff and comparing that with the cost and the remodeling hassle to beef up the structure slightly, I decided that the foam may be the least invasive means of giving me the "additional surety". And it's what I wanted originally anyhow. I asked the tile contractor to quote the use of these materials. His pricing communicated that he didn't want to use them. Or he thinks I'm his magical lottery ticket or something. I can install what I want for far less. And I will!
I looked at what it would take to beef up the structure to lessen the deflection and sag for "additional surety, if desired" as the the engineer's letter states. I have utilities going through that area, and I'm kind of tired of doing drywall work. I don't want to cut my subfloor open to access from the top. It's a big hassle, and doesn't resolve the issue that led to this thread.
The tile contractor's proposed work eliminated the traditional pre slope bed that is supposed to go under the mud bed. Plumbers are now laying the vinyl membrane flat on the subfloor. The tile guys are laying the sloped mud bed down and then applying a waterproofing membrane to the sloped mud bed to prevent water intrusion into the bed. If that membrane fails, the shower pan will not work as the traditional design where water is "exchanged", as there is no pre slope to guide the water to the drain weep holes. The way around this issue is to use a bonded flange drain with a waterproofing membrane. But bonded flange drains are not allowed in this municipality for some reason.
If the tile guy wasn't going to put in the pre slope bed, I was going to. After making a test pre slope bed, I started to think about the weight of the materials and the effect on the structure.
Before I started this project, I wanted the newer foam products to be used instead of the traditional methods. The tile guy doesn't use the foam products, and he wasn't even going to do the traditional method as it was designed. I have a penalty heavy contract with him, so firing him isn't very feasible. I may look into canceling the contract anyhow (I learned a lesson about signing these one-sided penalty-heavy contracts. Education isn't always cheap).
After pricing out the foam stuff and comparing that with the cost and the remodeling hassle to beef up the structure slightly, I decided that the foam may be the least invasive means of giving me the "additional surety". And it's what I wanted originally anyhow. I asked the tile contractor to quote the use of these materials. His pricing communicated that he didn't want to use them. Or he thinks I'm his magical lottery ticket or something. I can install what I want for far less. And I will!
Cheese
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[member=8843]Kodi Crescent[/member]...FWIW...Schluter offers along with the Ditra & Ditra-Heat, also what they call Kerdi-Shower which is also foam material. I'm in the process of installing a complete Schluter shower system as we speak. I went with Schluter just because of their long track record, thousands of installs and their "System" approach. They do offer everything needed to install a shower. [big grin]
http://www.schluter.com/schluter-us/en_US/Shower-System/Prefabricated-Substrates/Schluter®-KERDI-SHOWER-ST/p/KERDI_SHOWER-ST
https://sccpublic.s3-external-1.ama...10/8828763373598/Shower System Data Sheet.pdf
http://www.schluter.com/schluter-us/en_US/Shower-System/Prefabricated-Substrates/Schluter®-KERDI-SHOWER-ST/p/KERDI_SHOWER-ST
https://sccpublic.s3-external-1.ama...10/8828763373598/Shower System Data Sheet.pdf
Brice Burrell
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Cheese said:
I was not at all surprised to learn from a friend the knows a little Deutsche. He says that "Schluter Kerdi" translates directly into: "outrageously expensive". [tongue]
I guess I've never been sold on the Kerdi system, nor have I ever looked closely at the cost of the product/installation. I'd be curious as to why you see it as superior to a mudset/durarock install. [member=44099]Cheese[/member]
tjbnwi
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Brice Burrell said:
I've done the costing on various systems. Schluter has always come in costing less than "conventional" methods once all cost are factored in.
I can carry an entire 4'x4' shower system (walls, pan, and install material in one trip into the job).
Ditra heat is a great system.
Tom
Good for you putting your foot down on the pre-slope, it's very important and too often hacks neglect to do it.
I still feel your best bet is to remove the subfloor and bolt steel to either side of the joists wherever you can. You could honestly just put peices wherever there isn't utilities running and you'd take care of all the deflection. 3/8 steel on either side of a joist will strengthen it up very quickly.
I still feel your best bet is to remove the subfloor and bolt steel to either side of the joists wherever you can. You could honestly just put peices wherever there isn't utilities running and you'd take care of all the deflection. 3/8 steel on either side of a joist will strengthen it up very quickly.
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About two years ago a customer asked me to price a shower. I priced the Schluter system after reading recommendations here and reading up on it. The customer wanted to go cheaper and I wouldn't do what he wanted. A year ago I was asked to do some of the work in his bathroom and he had the tile guy doing the shower. He used the Schulter. Glad he did because what the owner proposed would have ruined his downstairs in just a few years.
Peter
Peter
I haven't used the kerdi panels but the kerdi membrane is fantastic. Have even used it under ceiling tile. Excelent bond and no leaks. Used their kerdi drain as well which makes it really easy to seal up and also allows a bit of wiggle room for tile-to-grate alignment.
If I had a weight load issue and kerdi panel could help solve it I wouldn't hesitate to use it.
If I had a weight load issue and kerdi panel could help solve it I wouldn't hesitate to use it.
TooManytoys
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While you are considering reducing weight of the installed components, and that always good when considering slow, long term deflection, you need to consider more just the live loads.
As long as the floor tile is one of the last components installed in the bath deflection from all the other installs will already have happened. So new and variable deflection will be people and tub water. Not that tub water won't be substantial.
In a kitchen there is more to it as the cabinets, refrigerator, stove and the items stored often deflect the floor after the tile is installed along with the people load. Unless your installing tile up to the existing cabinets.
Usually the calculators assume the worst case, the kitchens or other rooms load delta. Baths sometimes can be a little more deflection friendly but to get deep into the weeds you need a PE.
As long as the floor tile is one of the last components installed in the bath deflection from all the other installs will already have happened. So new and variable deflection will be people and tub water. Not that tub water won't be substantial.
In a kitchen there is more to it as the cabinets, refrigerator, stove and the items stored often deflect the floor after the tile is installed along with the people load. Unless your installing tile up to the existing cabinets.
Usually the calculators assume the worst case, the kitchens or other rooms load delta. Baths sometimes can be a little more deflection friendly but to get deep into the weeds you need a PE.
Peter Halle said:
I don't know much about what you are talking about, but glad to see you stuck to your method. It does sometimes pay to walk away. I do have several instances where I would not budge from my own ideas. A couple of years before i retired from my mason biz, i figured a fireplace & chimney with an unusual design above the roof. The plans and specs did not show any extra flashing where I thought there should be. I figured for the flashing and included it as an extra and included a note in my proposal that i would not do the chimney without that extra flashing. I lost the job.
six months after the owners moved in, I got a phone call from the owners wanting to know why the chimney was leaking. Their living room ceiling was soaked and they feared it would come down. The builder recommended waterproofing. The owners wanted to know if I would waterproof the chimney. I told them I knew exactly why the chimney was leaking and it would cost a lot more to fix the problem than they saved by doing the job wrong in the first place.
Once I got into the project, I discovered the flashing that was done at the roof was not even done correctly. I ended up tearing the entire chiney down to where it came thru the roof and doing that flashing as well as the extra flashing further up. End of leaking. I ended up with not only more mason work from the people, but a couple of years landscaping work when i closed down my mason biz. They also recommended me several other good accounts before they finally moved away.
That repair was done over 30 years ago. I still drive past a few times each summer and even tho the roof has been redone a couple of times, that copper flashing still has the patina of old aging. It has not been touched. What happened to the original builder? He went out of business (and out of town) soon afterwards. Luckily, I had not done the original job in the way specified.
Tinker
Kodi Crescent
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The product I'm using is the Durock Shower System, which is USG's answer to Schluter's Kerdi sytem. USG has the same components, and the foam is a bit more dense (stiffer) than the Kerdi panels. The wall installs are similar to the old Durock methods, and the floor and waterproofing installation is very similar to the Kerdi method.
They also have a custom shower pan service where you give the dimensions, and the factory uses a CNC machine to cut the slope to the drain location so you have a drop-in pan. This will be useful as my drain is not quite centered and I don't wish to move it. I don't want to "field modify" a stock pan, because my pan perimeters wouldn't be even. The custom tray service takes care of this.
The drain is bonded similarly, but just slightly different. The impression I got from watching the USG videos is they did some customer research with Schluter users, found all the Schluter shortcomings and corrected them. But then again, perhaps I'm mis-perceiving that.
The local tile supplier has a promotion going on to get the product out into the field. Buy 5 panels, get 5 free. Lucky for me, the fewest joint install used 9 panels. That drove the wall cost closer to the traditional Durock methods. I can use the scrap to make a custom niche instead of using the preformed product. (I have to reframe part of the wall first.)
I did have a PE involved. I appreciate the mention of the tile/floor deflection when the other stuff is added to the room. I had planned on tiling the floor before the cabinet goes in. I'll ask him about that as the cabinet will receive a quartz countertop, and the shower will get a quartz threshold and a glass door.
They also have a custom shower pan service where you give the dimensions, and the factory uses a CNC machine to cut the slope to the drain location so you have a drop-in pan. This will be useful as my drain is not quite centered and I don't wish to move it. I don't want to "field modify" a stock pan, because my pan perimeters wouldn't be even. The custom tray service takes care of this.
The drain is bonded similarly, but just slightly different. The impression I got from watching the USG videos is they did some customer research with Schluter users, found all the Schluter shortcomings and corrected them. But then again, perhaps I'm mis-perceiving that.
The local tile supplier has a promotion going on to get the product out into the field. Buy 5 panels, get 5 free. Lucky for me, the fewest joint install used 9 panels. That drove the wall cost closer to the traditional Durock methods. I can use the scrap to make a custom niche instead of using the preformed product. (I have to reframe part of the wall first.)
I did have a PE involved. I appreciate the mention of the tile/floor deflection when the other stuff is added to the room. I had planned on tiling the floor before the cabinet goes in. I'll ask him about that as the cabinet will receive a quartz countertop, and the shower will get a quartz threshold and a glass door.
Cheese
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Brice Burrell said:
[member=1146]Brice Burrell[/member]
Well...unfortunately Brice your friend does indeed know a "little Deutsche"...as in too little Deutsche. As luck would have it, I do speak German as a second language and however crude my communication skills are because of the regional German dialect differences, I have been able to communicate with my German friends when my job needs warranted it. If you google Schluter Kerdi on a German to English dictionary, the result will be...ready for this...Schluter Kerdi...not outrageously expensive...so I'm thinking that mumbo jumbo was just an internet joke.
I never suggested Kerdi was superior to the old school mud set process, but only embraced the Schluter process because it is a one-stop-shop, kind of like the Festool approach. Schluter has figured out what the outliers are and have compensated for them. What's not to like about that? Let's make our lives easier rather than more difficult...I'll install Ditra-Heat and Kerdi in my own bathroom and if the products are a total zero, I'll report back post haste. I find nothing wrong with trying new products and new approaches when the result will yield an enhanced result. That's the reason we now have refrigerators rather than ice boxes. [big grin]
[member=44099]Cheese[/member] I have been following this thread. Not that I will ever use any of the information from the thread and the research suggested (and read), but it has been most informative. But, really, what is the advantage of a refrigerator over an ice box? : 
Tinker
Tinker
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