Question about anchor bolts and pressure treated wood

chet · May 14, 2006, 01:11:35 PM

Been using da sleeve and washer fix with no problems from either the code office or the building inspectors. ;)

chet "a licensed Michigan residential builder"

DanG · May 14, 2006, 01:28:03 PM

I don't figger to have a problem with it either, Chet. But I'm gonna run it by them first, so there won't be any surprises. ;)

Another thing to worry about is the termite shield. Most folks use aluminum or galvanized sheet metal for this, but it may not hold up in contact with ACQ, either. If I remember right, the Fla. code recommends copper, but doesn't require it. I'm wondering if a rubber shield between the metal and the wood might work for this, too. I can get some high quality rubber sheeting from Mr. Hootie for a good price. I also wonder if vinyl would work for a termite shield?

UNCLEBUCK · May 14, 2006, 02:27:02 PM

I cant feel good about what might happen to brdmakr and the simplest fix is a redwood plate , I wont go into the history where I get my info but he said your comparing apples to oranges by comparisons of a nail or screw to a quality anchor bolt and a plop of grease . The redwood plate is quick and you allready have your pattern and then you will have a happy project boardmaker . Have a Happy Mothers Dinner somewhere today and start tomorrow a new ! ;D I am in Minnesota and built my shack to hurricane standards just because my grumpy old man always goes heavy when building . Please dont cut your anchor bolts out ;D

etat · May 14, 2006, 03:49:06 PM

A bit of research pretty much verify's what I thought.

What can you do to minimize galvanic corrosion? First, always try to eliminate the cathodic metal by making all parts of a structure out of the same material. When this is not possible, use nonmetallic, nonabsorbent insulators between the dissimilar metals to prevent current flow. For example, use plastic or ceramic washers and sleeves to isolate bolts as they pass through a plate of a different alloy instead of fiber and paper washers, which absorb water. guessing this would apply to the copper in the wood too. :

As stated, a major required component of galvanic corrosion is water, or moisture. Eliminate that and the corrosion will be minimized. Per Uncle Buck, I also agree that comparing a anchor bolt to a screw or a nail is to compare apples to oranges and per DanG and Chet agree that using piece of pvc as a sleeve would be a good thing.

I don't know if its code or not. On MY house I used aluminum flashing, then a rubber membrane between the blocks and the pressure treated plate, and...........

I drilled over sized holes and greased the anchor bolts with grease gun........

That said, I did use cca pressure treated (again, perhaps comparing apples to oranges). In fact, I built a bridge of the stuff inside my house over the stairs. Seems to be holding up pretty well.

Tom · May 14, 2006, 03:51:02 PM

Just to simplify y'all's conversation a little, the purpose of the treated plate is to prevent rot where wood touches concrete. Concrete will "wick" water and rot loves a place that is either damp or is a transition point between wet and dry. While treating a stick of wood will kill eggs or anything else in the wood and will deter its being eaten by insects later, the main purpose is to control rot.

Here's some of my 40 year-old book-learning from my dear professor, Dr. Paul. Dr. Paul is no longer with us and the world is sorely lacking in some of his down-to-earth explanations of insect behavior.

The first defense a home has from termites is the 18" that the first wood is from the ground. Many southern homes were built off-grade to allow air to pass beneath the house. It kept it cool in the hot summers. It also kept termites at bay. For some reason or another, the magic number 18 is where termites begin to tire from their assent up a pier and will turn around and go back into the ground. It is also a space that allows inspections of piers to reveal the tunnels that the termites have to build when they cross open areas. You see, termites will dry out and die if they aren't protected by the bark of a fallen tree or the tunnel they build. When you see these tunnels, tear them down and soak the pier with an insecticide. Even soaking the tunnels without tearing them down is good. This is a lot better than spraying the ground around the house where the weather can dissipate the poison.

The second defense is the termite shield. It is a flat piece of metal that has been designed to slope down from the pier. By covering the top of the pier it prevents termites from entering the beam from inside of the pier. This was especially important in days when wood was used for piers, but, even concrete or concrete block or rock can provide an internal path from ground to the beam. The second defense, the shield, also serves to deter by playing with a termite's psyche. Termites have an inbred desire to go up. When they encounter a shield, they are none too happy about having to go sideways, especially for any distance. Even if they happen to have a five star general that is making them build their tunnel upside down and sideways, they have trouble with the edge of the metal. It's difficult to build a tunnel that will stay intact when navigating that fine edge. Before they even get to the edge, they run into another part of the shield that is bent down. To a termite, this is all wrong. She's trying to go up and there is nowhere on the shield that will allow it. Frustrated, they go back.

Using the insecticides is just topping on the cake. A healthy spray of insecticide, wetting the pier to the point of run-off, will not only destroy the termite's tunneling efforts but will leave crystals of poison embedded in the surface of the pier that will help to deter them even longer.

Treated wood is really no deterrent. A termite will cross the 1 1/2 inches of treated wood ,used as a plate, with no effort at all. Ants will crawl over it as well as any other insect. They won't eat it, but it won't stop them from getting to the untreated stuff above.

The third defense against termites is "housekeeping". One should not allow weeds to grow near the foundation, nor vines to grow on the house because a termite needs just a twig to go inside of to attack the house. Shrubbery should be kept clear of walls for the same reason and it's a good idea to keep a treated area all the way around the base of the house that contains no vegetation at all. A tall, dead, Argentina Bahia grass stalk will form a bridge to the side of your house. By the same token, don't leave a 2x4, cane fishing pole, or old ladder leaning on the house either. Any contact with bare ground to the house with a piece of wood is providing a bridge.

I'm not fond of houses built on slabs. Slabs can crack and provide many entrance ways into a building. Slabs are also laid directly on the ground and don't provide that magical 18". Florida engineers, in all their new-found knowledge have decided that building on piers or off-grade is not a good thing. It lets hurricane winds get under the house and pick it up from the ground. They have been so concerned with the latest threat of hurricane, that they have almost forgotten that there are other threats to buildings too. If I ever build a new house in Florida, it will be off grade, even if I have to devise some crazy scheme to call it a second floor.

brdmkr · May 14, 2006, 04:27:51 PM

I just got back from pulling up the 2x4s I put down yesterday! I purchased a piece of 1/2"PVC and have already cut it into 11/4 " sections for sleeves. I also sprayed WD40 on the anchor bolts and cleaned them up a bit. Some were already showing signs of corrosion. My plans are to.

1) Call the BI and ask what others are doing.
2) Ask if a PVC sleeve and a galvanized washer will meet with his approval.
3) Ask why this is not more widely known about.

I checked at our local Home Depot and all they sell are galvanized anchors, but I spoke with one the other home center folks this morning and he said that they did not even carry them. My gut feeling is the concrete contractors don't even pay any attention. Anyway, my wife was asking me how people could even do things like this (speaking of the concrete contractor) and I told her that I'd bet that many of the general contractors in the area were unaware that the new PT would cause this kind of trouble. If it weren't for this forum, I wouldn't have any idea either!

Thanks for the sleeve idea. I'll keep everyone posted.

Don_Papenburg · May 14, 2006, 08:57:47 PM

Anothe rthought is ase non treated wood , it has been used for thousands of years. But Isolate it from the foundation.

I have found that if you are on cement block the wood over the cores is what rots first because the moisture has a direct path right to the wood.

chet · May 14, 2006, 09:34:26 PM

Quote from: Don_Papenburg on May 14, 2006, 08:57:47 PM
Anothe rthought is ase non treated wood , it has been used for thousands of years. But Isolate it from the foundation.

Check code requirements first! As many locations require the use of treated or rot resistant woods against any concrete or masonry.

brdmkr · May 15, 2006, 08:52:52 AM

Called the BI. I asked what other people were doing. He said 'nothing' and that it should not be a problem. I said OK. I figure it is better not to rock the boat. If others are not doing anything, I will use the sleeves and there should not even be any reason for the BI to remove the washers to check. If he did check, he'd just figure I was strange. I think he already knows that ;D In reality, I wonder just how bad it really would be if I did nothing ??? I wonder if anyone has actually done any research on moisture content of the PT and longevity of steel in contact with the ACQ. I suppose there are just too many permutations (wet wood in a dry space, wet wood in exposed setting, nails vs bolts, galvanized vs not, etc.). I might not worry about it if I could get everything in the dry in a hurry, but that is just not going to happen.

beenthere · May 15, 2006, 10:52:18 AM

brdmkr
Maybe this sill plate is a good place to use the plastic wood deck boards. :

Larry · May 15, 2006, 04:46:45 PM

I researched the question maybe two years ago and found with 1/2" anchor bolts the recommendation was no precaution's needed with ACQ...darn if I can name my source now. Iffen I remember right the reason was the corrosion would not weaken 1/2" and bigger fasteners enough to cause a loss of strength. Check with your ACQ provider and see what they have to say.

An alternative is to use the hot dipped galvanized plates in lieu of anchor bolts. The concrete finishers love em cause they can use the power trowel and not have to worry bout hitting anchor bolts. They are not approved by code in all areas...old fashioned but I like the "J" bolts best.

chet · May 15, 2006, 09:42:03 PM

The way I figure it, I gain peace of mind with da simple and cheap fix da sleeves and washers give.

Don P · May 15, 2006, 10:18:22 PM

One other thought that a comment sparked. A sill isn't ground contact so a lightly treated sill is fine. A .25pcf treatment for above ground use would do the job with less chemical in the wood, so hopefully less corrosion potential. I usually try to use .60 for posts and such. I doubt my inspector would pass a composite sill without an engineering report showing it was approved for structural use.

It's off topic :

;D, but here's another tidbit I learned last week.
It has always bothered me to notch into a piece of treated to find an untreated heart, heartwood isn't penetrated by the solution. Yes heartwood is more decay resistant than sapwood, but it still rots faster than treated. Foundation grade lumber and posts, for wood foundations, requires 6 or more rings per inch and no heartwood, so it should be thoroughly treated to .60. We dug for porch footers today at work, I'll try to source 6x6 FG posts and see how shocked I am.
I'm hoping to hear more on the treating Ron Scott posted about.

Kinda ironic that we've saved our kids from not being poisoned on the playground so they can participate in a deck collapse when they get to be college age :-\.

brdmkr · May 17, 2006, 10:27:53 AM

Well, I redid the sill plate! This time with some PVC sleeves and galvanized washers. I feel much better about the whole deal. It may not have been required, but I don't like buildling anything with the idea that I only want it to last for a little while. It may have lasted 20 years without a hitch, but I would have known that there was a potential problem. I just couldn't have felt good about it. To be honest, I may wind up putting stainless washers on. I really like the way the PVC sealed against the sill seal at the botton and the washer at the top. I cut them to 1 1/4 inch and cinched the washer down tight. The seal pushed up on the PVC a little and caused the PVC to contact the washer. There should be no contact whatsoever between ACQ and untreated metal. Of course, the galvanized washers may go someday, but I can replace them easy enough. Thanks for all your feedback. When we build the house, it will be STAINLESS all the way!!!!

florida · May 17, 2006, 04:38:07 PM

Here's a link to a corrosion FAQ by Simpson Strong Tie.

http://www.strongtie.com/productuse/selection-guide.html

Don P · May 17, 2006, 10:39:20 PM

Thanks Florida,
Am I reading right? For interior dry use their Z-Max fasteners are the minimum. Exterior wet or dry is high risk and should use stainless.

I notice they haven't tested above .40 pcf on the ACQ lumber. They then go on to state that ammonia is much more corrosive. My understanding of the chemistry is poor, but the A in ACQ is from ammonia from what I understand ???. If that's the case I haven't built a deck right since the changeover and I've been trying, stainless should be the off the rack material.

florida · May 18, 2006, 04:55:06 PM

You're reading it correctly. I know a couple of guys who built decks using Z Max connectors and hot dipped nails. When the decks were a little over a year old they got concerned because of all the new information that had come out since the decks were built. In both cases the 16 # nails were corroded down to the size of 6# finish nails. Both decks had to be totally torn down and rebuilt with stainless connectors and nails. Don't take any chances with ACQ. However, in my area and I'm sure most of the country you can also get Borate treated lumber which works fine for botom plates and doesn't need special fasteners. We use borate inside and ACQ outside.

Don P · May 19, 2006, 10:41:00 PM

Our homeowner is trying to hunt down and price the stainless hardware. I've been thinking today about a detail to avoid or at least back up the hangers. This is what I've been thinking about for the outer rim/ post area.

I'm no arteeste :

The lower girder under the joist in our case will probably be a double 2x10, I'll notch it into the 6x6 post 2-1/4" deep (a band and a half). The joist bear on it, hangers on the rim can fail or are really unnessecary, could be coated screws. The bearing points are on wood. In the future I'm thinking I'll do something similar against the house whenever I can ???.

florida · May 20, 2006, 07:41:05 AM

Your plan would work fine and no hangers would be necessary at all. You need to double the 2X under the joist to provide proper support then the 2X on the ends of the joist becomes a band board. If you live in an area which requires uplift protection a much cheaper hurricane clip would work to attach the joists to the girder. You can get stainess nails, screws, hangers and clips from http://www.mcfeelys.com/index.asp hardware.

urbanlumberinc · May 20, 2006, 10:59:41 AM

Can't believe you guys still use PT lumber for sill plates! LSL is the only way to go. Perfectly straight, flat, doesn't split, warp or splinter, and the best part of all, no need to spend money on hot dipped fastners. Boise makes it in 2x4x18' and 2x6x18'. It's also great for doing round walls, balloon walls and anything else where you need dead nuts straight lumber. It's also rated for ground contact.
I found out the whole ACQ hot dipped fastner thing out the hard way. Inspector made me go round the whole house and pull all the non galv nails out of the ACQ sill, and nail it off with hot dipped sinkers. Same inspector busted my buddy for using ACQ for plates on floating bsmt walls. He pinned the walls with 60's that weren't hot dipped then found out the hard way that there's a huge price difference between hot dipped 60's and non galv.

DanG · May 20, 2006, 11:24:53 AM

Thanks for the link, Florida. I'll keep it in mind if I can't find the stuff locally.

Welcome to the forum, urbanlumberinc! I'm not familiar with LSL. Could you bring us up to speed on it?

beenthere · May 20, 2006, 11:52:46 AM

urbanlumberinc
Are you saying that LSL (laminated strand lumber?) can be used in places where treated lumber is required by code? Seems LSL would not be a substitute for treated lumber.

Here is a link of one mfg. LSL product

urbanlumberinc · May 20, 2006, 09:02:18 PM

I've been usind LSL in place of ACQ or CCA treated lumber as sill plates, ground plates on floating basement walls and anywhere else where code would require treated lumber. Awhile back the Denver inspectors started busting people for nailing floor joists and plywood sheets to ACQ without using hot dipped fastners. I'd tryed the Borate treated stuff and the Silica stuff before discovering Timberstrand. Lemmee see if I can find some info on the web and post a link.

urbanlumberinc · May 20, 2006, 09:07:08 PM

www.trusjoist.com
doesn't have any specifics about the approved uses of LSL but it does have a bit of info that may be helpful.

beenthere · May 20, 2006, 10:26:23 PM

urbanlumberinc
I'll read that cite again, but I'd be willing to bet that untreated LSL should not be used in places where treated lumber is required, which would include the sills that this thread is discussing regards pressure treated wood.

I too cited the trusjoist .pdf in my previous post, and it says ""LSL shall be limited to interior dry conditions and must be protected from weather exposure during construction"". Wouldn't you think that implies it is not resistant to decay and will swell if allowed to get wet?

In your trusjoist link, there is a .pdf on treated sills and plates, where the LSL is treated with zinc borate and recommended. Maybe you are using zinc borate treated LSL for sills?
treated LSL sills with borate