Embedding non PT wood in masonary wall
Krico
| Posted in Construction Techniques on
I am rebuilding a garage flat roof with new joists and new plywood. The old joists were inserted into pockets in the masonry walls of the garage. To get the slope of the new joists to fall correctly, I need to pack mortar into the pockets around the joists. Since the new joists are not pressure treated, should I do anything to protect the ends of the joists. I was thinking of wrapping the ends in something like roof ice and water shield, but don’t know if it is necessary to do that. Can someone let me know if this is necessary and if this the correct approach.
Thanks
-Kevin
Replies
Why you packing with mortar?
if you're packing mortar to elevate the joist you;ll be better using PT or steel shims.
to protect the non-PT wood from absorbing moisture from the masonry, you can warp with felt or peel & stick.
I am packing to elevate them. Would a lumber yard carry steel shims?
you could try. I have a kinda local steel supplier I use for mine. Thre's nothing wrong with using PT either.
That's two votes for PT. Just take the other material back to exchange it and pay the difference. No matter what you use to treat the wood it wont be as good as pressurizing the treatment into its core. With the pressure treated joists, you wont ever have to worry about it again. In fact, I'm assuming that one of the reasons you are having to replace them is because moisture wicked into the ends from the concrete block.
no need for the extra costs of PT joists when all he needs is PT shims. or steel shim stock if he can find it easy enough.
I am going to look for the steel shims. I need them for another project. If I can't find them, I will go with the PT shims.I am replacing them because this is a house that I bought recently to rent. The roof on the garage was in really bad shape. There seems to have been a fire up there at one time.
You won't find them called shims. You'll want to look for steel plate in varying thicknesses to suit your needs. You may be able to find a steel recycler nearby that will sell. You don't need any glamorous alloy, just something to fill the space. Rustoleum spray if you want.
Edited 7/22/2008 8:45 pm ET by john7g
If you decide to use steel shims, You can pick them up at any industrial supply co.? bearing distb. also carry them they also come in hydensity plastic that are known as Redishims and or Plastishims they are use for alignment on industrial machinary.
very cool tip!
Plastic shims are also used to shim the concrete walls on tilt-up buildings. Hard to imagine those little shims supporting tons of concrete and roof.
As others have said, shimming is probably an easier way to go than packing mortar into the joist pockets. There is nothing wrong with metal shims, but wood shims will work just fine.
But you don't need PT poisoned wood joists. Naked, untreated framing lumber has been used in contact with concrete ever since portland cement was invented, and there are no 'issues' with the concrete adversely affecting the wood, despite the modern propensity for idiot code writers to imply the contrary. I will wager there are at least 50 million homes in the U.S. alone with untreated sole plates sitting on the concrete.
More importantly, if you're gonna use metal shims, you really don't want the new PT lumber sitting on them unless the shims are made of stainless or are double-hot-dip galvanised. ACQ has a nasty tendency to eat away at anything less robust in a very short time.
Dinosaur
How now, Mighty Sauron, that thou art not brought
low by this? For thine evil pales before that which
foolish men call Justice....
Good post!!!
Thanx. Just another two cents spent in the ongoing battle to defeat Big Poison....
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
I get so upset with the BI that think that plates have to be PT when all you need is a seperation from the concrete.
Personally, I think that anything that dissolves steal can't be good to touch!
But I don't think the OP had any plans of using PT joists. I suggested PT for shims since it's my opnion that CC and even CMUs (which I'm assuming are what compose the wall that these joist/beam pockets are in) are always bleeding some kind of moisture. That moisture will whick into any non-PT lumber that's in contact with it reducing the longevity of the components & the labor.
My house is on a slab with mostly PT sill plates, except for the shower stall framing. I jacked up the wall and replaced it. Then I flipped the plate over and had a look-see. Now, what were you saying again?
arcflash.
Your conditions are not those of the OP.
He had rot, you didn't! What may have prevented yours from rotting are a variety of things most likely due to local soil conditions. Also local climate can affect things as well as construction techniques used.
When I say local conditions I do mean just that.. you may be exempt from the problem while a few homes away they have trouble.
The code is written for national standards. If you have decades of experiance successfully doing something a particular way that does not mean that the matter is unimportant.
In the case of the OP he did nothing to change the masonary wall which had rotted. so additional protection is required to prevent rot from reoccuring.
...PT sill plates, except for the shower stall framing. I jacked up the wall and replaced it. Then I flipped the plate over and had a look-see. Now, what were you saying again?
I was saying that, contrary to an unfounded yet widely held belief, it is not necessary to use poisoned wood whenever wood and concrete touch.
I was saying that there is a regrettable tendency by idiot code-writers to believe the propaganda disseminated by the PT industry, and to incorporate that belief into building codes in spite of an enormous amount of physical evidence to the contrary.
I was saying that, there are literally scores of millions of homes out there in the U.S. landscape with not a stick of PT in them, and they are in perfectly good shape after 50+ years.
The real question is, what are you saying?
IIRYR, you are saying that because the shower stall framing in your house was not made of PT lumber, it rotted.
I beg to differ. The reason your shower stall framing rotted is that the shower stall was not properly constructed.
A properly constructed shower stall prevents water from getting to the framing in the first place, so there is no need for the framing material to be rot resistant. It is the same for a properly constructed roof, and any other portion of a building which is exposed to water. All good building design and construction is based on that essential, elemental, fundamental premise.
The increasing reliance on PT to compensate for sloppy technique and bad design not only reflects but helps to propagate a poor attitude with regard to proper construction technique, from architects through code-writers all the way down to the guy with the hammer. This tendency is ultimately destructive, and should be discouraged at every opportunity.
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
The shower was waterproofed, long before the framing issue was revealed. Water was not getting behind it. The slab has a vapor barrier. The sill wasn't rotted, but left to itself, it was obvious that it would eventually. I dont think that the use of pressure treatment is to make up for shoddy work (it may in many cases, though). I just look at it as insurance. Even when I use regular old pine as blocking for instance, I like to treat my field cuts with a waterproofer. Good carpenters have have been doing it long before me. If I've got pressure treated boards laying around, I'll use them. It saves me time, and sometimes money, and I've got insurance just in case all of those other extra measures and pain staking details I sweat over fail. Lumber is dead plants. Waterproofing it just buys a little extra time.
Okay, so it seems I misread your post. What exactly had rotted that you needed to jack up the wall and replace it?
As to insurance, I understand your point but I don't insure my place against theft or vandalism by hiring the local hoods to 'protect' it. Putting poison in your home is asking for long-term problems down the road. Remember that when lead-based paint (to give just one example) was in common use, nobody thought it would one day be considered dangerous. It was simply seen as a better, more long-lasting paint product. Insurance, if you will.
In the modern corporate world, marketing concerns will trump R&D every time. As soon as a new product looks like it will outlast the guarantee the marketing dept. thinks it has to offer to sell it, management will put it on the market. Long term testing doesn't happen, because no corporation is willing to wait 30 years or more to see what happens to their latest witch's brew in the real world. Accelerated computer modeling is considered enough.
Duh. And double-duh to us for buying it.
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
Edited 7/25/2008 12:46 pm ET by Dinosaur
It wasn't the entire wall, it was an untreated mudsill that was used (don't ask me why, the sill itself wasn't but about four or five feet long). It also hadn't rotted, yet, but judging by the staining and fungal growth on the bottom of the plate, a year or two tops would show a spongy, structurally unsafe bathroom wall, I was convinced. There are poisons in the foods you eat and the air you breathe, and almost every building material we build with is not safe to be exposed to while you are cutting, drilling, or burning it. Just about any man-made chemical is not safe for you in prolonged moderate doses. Why the battle with pressure treatment? Studies have shown that the effects on the environment are no worse than most building materials that can be used, and the new treatments are showing even safer levels. I choose to use it because I know that I will have that much more time before I have to go to the lumberyard and buy more lumber to replace that board, I'd even call that helping the environment. So, you build your decks with standard white pine, and I'll stick to white pine that has been treated.
Why the battle with pressure treatment?
'Those who ignore the lessons of history are doomed to repeat them.'
I am doomed enough already; don't feel like adding any additional dooming to my schedule.
But seriously, it just isn't necessary. And that makes it a waste of resources if nothing else. If you want 'insurance', use a naturally rot-resistant species such as cedar, hemlock or any of the many others. Save the copper for making pipes or pennies or anti-arthritis bracelets....
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
Cedar is more available in my market, but I would never consider it for a structural application. It is too light and flimsy. I have got other things to do than to convince you of my point. It is not a conspiracy, it is proven and common knowledge. I don't mind that you don't like pressure treated wood, don't buy it. Just don't tell me that I shouldn't.
Edit: I know cedar is popular with decks and things, I wired a house once that I swore had cedar studs. I can't even remember where I heard it, but I was told not to do any signigicant structural work with it. I'd think that if you could, cedar studs would be sitting close to the PT 2x4 at the local lumberyard. Thoughts, anyone?
Edited 7/25/2008 2:12 pm ET by arcflash
How about seperating the concrete from the would. ie, sill seal?
I agree that would be a good approach. But I do have concerns about moisture getting trapped between the sill sealer and untreated lumber. Bear in mind, that I don't have very much experience with your particular method. I'd say about all untreated sills that I have ever seen were on a wood subfloor, and therefore, sill sealer or pressure treatment were not required. Now I have seen sill sealer AND pressure treated plates used on a hollow block foundation. Couldn't tell you if it was effective or not.
i agree with you as my home has cedar floor joists imbedded in the stone walls and rough lumber imbedded in the walls for attaching the walls inside they seem to have past the test of time as none are rotted
by the way the work was done in 1875 according to the stone marker over the front door
... the test of time....
The only one that really counts...in the long run.
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
A lot less of a concern than water into wood from concrete surfaces.
I have a tendency to agree with Dinaseor(SP), just a little protection from the concrete.
I have seen a lot of poured basement floors, with no treated wood or any other protection from the concrete, and the plates are in good condition. I suspect most have no vapor barriers under the concrete either. I wonder if there is a connection?
I would cut shims from PT and not bother packing with mud
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