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Alton
Veteran Member
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| 13 Feb 2012 09:54 PM |
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I try to avoid using typical treated wood inside the space that contains the air I breathe. Using treated wood beyond the conditioned space is ok and would probably deter termites and other pests from eating or gnawing on it. Cost wise, I would probably use untreated Glulams sitting on G90 thin steel sheets slightly larger than the footprint of the beam. There are some types of treated wood that are perfectly safe for people and the environment. See TimberSil, heat treated wood and demineralized wood to name a few. |
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Residential Designer &
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Lbear
Veteran Member
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| 14 Feb 2012 02:42 AM |
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Posted By Alton on 13 Feb 2012 09:54 PM
I try to avoid using typical treated wood inside the space that contains the air I breathe. Using treated wood beyond the conditioned space is ok and would probably deter termites and other pests from eating or gnawing on it. Cost wise, I would probably use untreated Glulams sitting on G90 thin steel sheets slightly larger than the footprint of the beam. There are some types of treated wood that are perfectly safe for people and the environment. See TimberSil, heat treated wood and demineralized wood to name a few.
The thin steel sheets is a good idea. I assume the G90 sheets would be installed AFTER the concrete cured? Not a big issue but one would have to drill holes in the sheet metal so that it would go through the anchor bolts on the wall. I wonder if more people like the OP experienced problems of the wood boards twisting? If so, it can cause the roof area to create gaps where the roof meets the ICF wall. |
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Alton
Veteran Member
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| 14 Feb 2012 02:18 PM |
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Lbear,
The spacing of the anchor bolts are offset from the spacing of the floor trusses or rafters above. If done correctly, there will not be any conflict with the small galvanized steel plate and the anchor bolts or hurrican tie downs. In other words, holes will not have to be drilled for the steel plates - only for the dimensional lumber such as 2x6s, 2x8s, etc. In fact, the applications that I have seen in Florida have nothing other than the weight of the roof holding down the metal plate. Of course, the hurricane tie downs hold the roof in place.
I believe the problem with treated lumber twisting, cupping, warping, splitting, etc. is only with the wood that has received the wet chemical process. The other types of treatment that do not cause the wood to soak up a lot of chemicals should not have these problems. |
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dmaceld
Veteran Member
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| 14 Feb 2012 04:22 PM |
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Posted By Alton on 14 Feb 2012 02:18 PM
I believe the problem with treated lumber twisting, cupping, warping, splitting, etc. is only with the wood that has received the wet chemical process. The other types of treatment that do not cause the wood to soak up a lot of chemicals should not have these problems.
Wasn't my experience when I built my house in 2008. I swear every time I picked up a nice straight 2 x 4 9' stud off the bundle outside and carried it into the house it decided to turn crooked as soon as I passed through the door and put it on the saw!  Virtually every 2 x 6, 2 x 8, 2 x 10, and 2 x 12 I received from the lumber yard was cupped, warped, twisted, or bowed. These were all nice dry untreated Construction grade Douglas Fir boards. I wish I would have used Structolam, or whatever they're called, to build the wall around my Jacuzzi. It would have been all straight and not have a slanted top like it does now. We replaced a handful of studs, in place, because they bowed after they were in the wall frame. |
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| Even a retired engineer can build a house successfully w/ GBT help! |
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Alton
Veteran Member
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| 14 Feb 2012 04:37 PM |
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I think the problems you saw are mostly attributed to new growth trees being barely large enough for the dimensional lumber cut from them. I do not think that larger, old growth trees cause as many problems. Maybe it is time that more of us start using engineered lumber like Timberstrand for wall framing and rim boards. Maybe more volume sales would result in lower prices. At least it would be free of most of the problems that we see with new growth lumber.
I think lower prices for engineered lumber would greatly increase its use. Builders and homeowners will stay with regular lumber as long as the price is less.
I also would like to see more people using synthetic lumber instead of treated lumber for decks. Too much maintenance with the wet process treated lumber. |
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jeepster
Basic Member
Posts:153
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| 14 Feb 2012 07:31 PM |
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A couple of comments related to a variety of posts:
1. I don't see how running anchor bolts every 2' vs. 4' will effect cupping, unless you ran two anchor bolts side by side every 2' or so. If the anchor bolts attach in the middle of the board, it'll still allow for cupping on either side of the anchor bolt.
2. I don't know the perms for the foam sill sealer, but I'd have to believe that it's keeping any moisture from the sill. The cupping might be due to concrete being cold and "pulling heat" from the board. The direction of heat conduction to the concrete might contribute to cupping. This is a theory . . .
3. If you have your stuff together the day of the pour, you can mark the truss location on the block and set your rafter ties into the concrete. Support a laser and use a detector to sink the ties in their respective locations. Then, before setting your trusses, wrap the bottom cord with a tar paper or equivalent. Obviously there would be no room for error, but if you know your truss locations, then it's not that big of an issue.
4. Regarding the OP, I doubt that cup will flatten. I would spray foam the gap and continue on with construction. That pic didn't look like a truss was above the icf. Was that a wall or a roof truss?
5. Lastly, using pressure treated lumber might be tricky, but that's how I'd go. If you have the time and the storage, buy the wood early, stack it in your garage with stickers (spacers), and let it dry for a few weeks. Maybe even run a fan on it if it's real wet. Rotate the stack and pull the warped ones out and return them. You might make some enemies at the lumber yard, but you want straight flat wood.
6. I don't think you will breath any of the chemicals used in pressure treating. 100% of that lumber is covered by drywall. The pressure treated bottom plates in a basement/conventional house would have an easier time mixing with the air than the top plate/window bucks. Also, one needs to put it in perspective. Formaldehyde found in particle board (mdf trim??, counter tops, cabinet shelves/backing), is way worse. |
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Chris Johnson
Advanced Member
Posts:878
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| 14 Feb 2012 08:15 PM |
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Consider steel studs for walls and roof trusses.
You could also consider a metal tie wet set into the top of the pour to attach the trusses to, no top plate requires, however you must have your truss layout marked on the wall prior to pour so as when you set them they are perfect |
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| Chris Johnson - Pro ICF<br>North of 49 |
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Dana1
Senior Member
Posts:6991
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| 15 Feb 2012 11:52 AM |
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Posted By lumberjill on 13 Feb 2012 06:07 PM
We just had the building inspector look at the gap, and he thinks it's just a matter of the sill board bowing due to being moist on one side (concrete side) and dry on the other, he suggested cutting wood and glueing into the gap and installing hurricane brackets attached to the roof truss and to the sill plate. We are in Alberta, has anyone heard of this and is it a common occurence
Jamming a wood shim in there won't stop the moisture migration. Short of lifting it off the foundation and inserting a proper capillary break, in gaps that large you could lay in some 6-mil poly atop the foundation as the capillary and fill the gap with 1-part expanding foam as an air seal. Wood (even pressure treated) shouldn't sit directly on the concrete, since the shifting dimensions from changing moisture levels creates significant air leaks. |
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Lbear
Veteran Member
Posts:2740
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| 15 Feb 2012 09:10 PM |
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Posted By Dana1 on 15 Feb 2012 11:52 AM
Jamming a wood shim in there won't stop the moisture migration. Short of lifting it off the foundation and inserting a proper capillary break, in gaps that large you could lay in some 6-mil poly atop the foundation as the capillary and fill the gap with 1-part expanding foam as an air seal. Wood (even pressure treated) shouldn't sit directly on the concrete, since the shifting dimensions from changing moisture levels creates significant air leaks.
The galvanized sheet metal would work as a capillary break, don't you think? |
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Dana1
Senior Member
Posts:6991
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| 17 Feb 2012 04:08 PM |
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Posted By Lbear on 15 Feb 2012 09:10 PM
Posted By Dana1 on 15 Feb 2012 11:52 AM
Jamming a wood shim in there won't stop the moisture migration. Short of lifting it off the foundation and inserting a proper capillary break, in gaps that large you could lay in some 6-mil poly atop the foundation as the capillary and fill the gap with 1-part expanding foam as an air seal. Wood (even pressure treated) shouldn't sit directly on the concrete, since the shifting dimensions from changing moisture levels creates significant air leaks.
The galvanized sheet metal would work as a capillary break, don't you think?
Yup! Metal capillary breaks are as good as it gets (but metal capillary breaks also introduce a thermal bridge to be factored in.) In termite-prone areas copper flashing would be even better. |
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Lbear
Veteran Member
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| 18 Feb 2012 12:48 AM |
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Posted By Dana1 on 17 Feb 2012 04:08 PM
Yup! Metal capillary breaks are as good as it gets (but metal capillary breaks also introduce a thermal bridge to be factored in.) In termite-prone areas copper flashing would be even better.
Would you have to still use treated wood if you have a metal capillary break between the concrete and wood? |
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cmkavala
Veteran Member
Posts:4327
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| 18 Feb 2012 07:14 AM |
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treated wood should not be in contact with steel
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| Chris Kavala<br>[email protected]<br>1-877-321-SIPS<br /> |
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Chris Johnson
Advanced Member
Posts:878
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| 18 Feb 2012 09:34 AM |
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Back at the start of the post the picture appears to be a large 2x10/2x12 built in Calgary so probably 1/2" Anchor Bolts @ 4' or greater on center
Moisture had caused the plate to twist and check and based on the size of the plate and spread of the bolts not much to hold it in place and this gave the poster the unfortunate results they see.
There is not real affordable solution or repair, again unfortunately have to live with it...short of removing the roof
Moving forward, quick and easy solution for future folks,
Built ICF to top of wall/underside of ceiling joists
Make a trowel tool, piece of 2x6 (for 6" core wall, 2x8 for 8" core wall, etc) we make ours with a 2x6 scrap, piece of scrap plywood to ride the top of the wall and a handle (I'll post a pic later)
Place concrete and finish with trowel, 1 1/2" lower than top of ICF
You still need to use a regular trowel to clean up the top of wall, the homemade trowel is rough but gives you an accurate distance
Set your Anchor bolts as prescribed by code/plan/engineer
The next day or so, use PT lumber, mark and drill to your Anchor Bolts and place in, you can use a bead of low expansion foam to seal between the concrete and PT if you are worried about any air snaking it's way around the area
You may still get a little twisting, but the point is the smaller the top plate the less the twist.
I'm almost tempted to suggest not installing the top plate until the day before you are planning to set the roof, this gives the concrete more time to cure and moisture to escape |
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| Chris Johnson - Pro ICF<br>North of 49 |
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Alton
Veteran Member
Posts:2164
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| 18 Feb 2012 10:36 AM |
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Installing a polyethylene sill sealer on top of the new concrete wall can also limit the transfer of moisture to the wood plate. As an alternative to polyethylene, installing galvanized steel sheet between the concrete and wood may allow the use of non-treated wood for the top plate or sill. Using copper would be ideal but much more expensive than galavanzed steel. |
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Farmboy
Basic Member
Posts:356
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| 18 Feb 2012 11:56 AM |
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As Chris suggested, we kept concrete 1.5" from top of wall with a jig my wife made. Used non-treated wood separated from the concrete by pink sill seal. This was a small pumphouse over our water well using 4" forms.  .  |
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Lbear
Veteran Member
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| 18 Feb 2012 08:08 PM |
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So the better option is to use UNTREATED wood but separate the wood from the concrete by a capillary barrier?
I still think utilizing a Glulam beam with a capillary barrier is the best option. Treated wood will ALWAYS bend, twist, split and warp. When a roof is attached to such a piece of wood it will cause the roof to move ever so slightly, but still move.
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dmaceld
Veteran Member
Posts:1465
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| 18 Feb 2012 11:19 PM |
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Posted By Lbear on 18 Feb 2012 08:08 PM
So the better option is to use UNTREATED wood but separate the wood from the concrete by a capillary barrier?
I still think utilizing a Glulam beam with a capillary barrier is the best option. Treated wood will ALWAYS bend, twist, split and warp. When a roof is attached to such a piece of wood it will cause the roof to move ever so slightly, but still move.
The Glulam would be the best from the standpoint of staying straight and flat, but it will cost a lot more. Really, my opinion is that the twisting and cupping isn't great enough to get wrapped around the axle about. Plus, you can pull it down close to flat with the nuts on the anchor bolts. And you'll probably never see the impact in the finished ceiling. This is one of those aspects of building where, in my opinion, you may be focusing on fleas, and in the process forgetting to get rid of the rat that's carrying them! I used untreated doug fir 2 x 10 and 2 x 12 on top of the walls. They were warped, twisted, and cupped to a fair degree. You can't see the impact at all in the ceiling. |
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dmaceld
Veteran Member
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| 18 Feb 2012 11:22 PM |
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Posted By Chris Johnson on 18 Feb 2012 09:34 AM
I'm almost tempted to suggest not installing the top plate until the day before you are planning to set the roof, this gives the concrete more time to cure and moisture to escape
I would say that is a good idea. However, the longer you wait to anchor the 2 x onto the wall, the more time you give it to twist and warp sitting in the lumber pile. I don't think there is a fool proof way to win the twist dance! |
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| Even a retired engineer can build a house successfully w/ GBT help! |
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Lbear
Veteran Member
Posts:2740
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| 19 Feb 2012 02:04 AM |
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Posted By dmaceld on 18 Feb 2012 11:19 PM
The Glulam would be the best from the standpoint of staying straight and flat, but it will cost a lot more. Really, my opinion is that the twisting and cupping isn't great enough to get wrapped around the axle about. Plus, you can pull it down close to flat with the nuts on the anchor bolts. And you'll probably never see the impact in the finished ceiling. This is one of those aspects of building where, in my opinion, you may be focusing on fleas, and in the process forgetting to get rid of the rat that's carrying them!
I used untreated doug fir 2 x 10 and 2 x 12 on top of the walls. They were warped, twisted, and cupped to a fair degree. You can't see the impact at all in the ceiling.
It is not the aesthetics that I am worried about, it is more the functionality. If a board starts to twist, in essence it will also split. Now imagine that 2x splitting where a SIP screw or truss anchor plate is holding it. You get enough of those spots in the board and you can have some serious issues if a high wind comes in or if you get seismic activity. |
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dmaceld
Veteran Member
Posts:1465
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| 19 Feb 2012 02:22 AM |
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Posted By Lbear on 19 Feb 2012 02:04 AM
It is not the aesthetics that I am worried about, it is more the functionality. If a board starts to twist, in essence it will also split. Now imagine that 2x splitting where a SIP screw or truss anchor plate is holding it. You get enough of those spots in the board and you can have some serious issues if a high wind comes in or if you get seismic activity.
Go to www.strongtie.com and look up hurricane tie. You'll find plenty of options that aren't affected by splits. To paraphrase the words in Hamlet, "Methinks thou doth protest too much." |
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| Even a retired engineer can build a house successfully w/ GBT help! |
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