I see there’s another thread under this heading on deck ledger attachment. I thought this might be of interest to someone.
Someone on the forum here recently suggested to me the use of Maine Deck Brackets. I just finished replacing a deck that was built on untreated 2x8s sistered onto 2×10 floor joists and extended out 10′ for a deck. Once I removed all that junk, I had to install a rim joist to which the new deck would be mounted. I was concerned about the rim joist pulling off, so I bolted through the Maine deck bracket, through the rim joist, through a Simpson predeflected holddown, which was fastened to the side of the joists. See pix. I can’t see any way that ledger is coming off of there without taking the house with it. (Well, maybe a slight exaggeration.) All bolts are 1/2″ stainless.
Also, I just bought a PC palm nailer and used it for the hangers on this deck. Great!
Replies
Looks like a great product, Tim. Where do you buy that?
I mean something more specific than "Maine"
Excellence is its own reward!
Here's the link.
http://www.deckbracket.com/
Thanks, but wow, they don't give them puppies away!
I see that Viking is listed as a dealer, I'll see what they sell them for. The concept is good..
Excellence is its own reward!
Here's the pricing link, if anyone is interested.
http://www.deckbracket.com/currentpricing.html
At $21 each plus shipping, they sure are expensive.
I didn't see any info on their website about design loads - Like how much weight each bracket will carry. Seems like that would be pretty important to them.My Wife said if she ever caught me downloading dirty picture off the internet, she'd wash my mouse out with soap.
Pretty slick. Though I side with Piffin, for a short piece of funky extruded aluminum I-beam, they're asking a lot. Still, I can see where they have possibilities.
I read the BOCA report and probably need to ask the manufacturer a few questions. It states that design loads (in the report) are limited to the bracket being attached to a 2x6 PT SYP. (That's a restriction based on the BOCA report only. The mfr should be able to specify the brackets use on wider material.)
My primary concern with this bracket is with the new PT lumber. A lot has been made on how aluminum should not be in contact with the new stuff, yet this bracket is aluminum. That means sandwiching some other material between the bracket and rim joist of the house and deck ledger?
Just wondering
.
Oh No! You really mean this stuff eats AL too?.
Excellence is its own reward!
For lunch. Dinner, and all aftermeal snacks. According to the FHB article this month, Al flashings need to be avoided at all costs (or words to that affect) because of the deterioration of Al when exposed to high copper concentrations.
Or are you just funnin with me?
Edit, I'm assuming that if Al flashings can't be in contact with the stuff, neither can any other Al product.
I never met a tool I didn't like!
Edited 12/11/2003 3:46:47 PM ET by NickNuke'em
Not funnin'
I had missed the AL connection.
Excellence is its own reward!
In an IRC code seminar I went to we were taught that AL flashing cannot be used in contact with PT lumber or cement. On several decks that I have replaced, I found that the old AL flashing was all eaten up - decks were not that old either. On the other hand, a think a thick piece of AL like those brackets would probably last quite a while. Matt
It probably wouldn't be hard to isolate it from contact with a pice of peel and stick.
I first thought these were pretty expensive but thinking that I would need them every two feet but it looks like longer spans could work depending aon the size and load of the porch. Three or four would work well fop most decks. But I do believe I could make them cheaper if I had my hands on an AL I-beam.
Excellence is its own reward!
is it possible these brackets are anodized? and if they are, would that provide sufficient protection to the aluminum? just wondering.
m
Mitch's question "is it possible these brackets are anodized? and if they are, would that provide sufficient protection to the aluminum?" got me thinking. Really I didn't even know what anodized aluminum is, so I did a web search. This is what I found:"Anodizing is a type of electrolysis used to place a protective oxide coating on metal. The metal acts as the anode (positive pole) of an electrolytic cell. Negatively charged oxide ions pass through a solution called an electrolyte, and oxidize the surface of the metal. Special treatments give the metal a porous outside layer that can absorb dyes. This makes it possible to produce colored surfaces that cannot be rubbed off or scratched."
and
"How to distinguish the coating surfaces? Use a white tissue to wipe the aluminum surface in a spot 6 to 10 times then check the tissue and the surface. If the tissue turn to black and that wiped aluminum surface changed color then you will know this is not an anodized aluminum."
I remember from my boating days that anodized aluminum is often used in that application but have no idea if it would help in this situation. Also, I gotta wonder a little about aluminum used in a structural (loaded) application, but think Piff's idea of the peal and stick would protect the metal adequately. For an already installed application, I might just loosen up the assembly and slide some builders felt in here between the AM and PT lumber.
Also, from the manufacturers' web site: "Will the brackets or screws rust ? Maine Deck Brackets are made of a highly corrosion resistant, tempered aluminum alloy, and will not rust. "
Yea, well we know aluminum won't rust.. I guess tempered aluminum is stronger... I thought tempering was a hardening process though... Mfg web page says that if you have questions about loading, "see your builder".... :^) Seems like they should make some specific statements with respect to load carrying capacity...
Matt
Edited 12/13/2003 9:35:12 AM ET by DIRISHINME
A little more on anodizing......
The oxide coating that is created is of course aluminum oxide. And it has a property such that it forms a continuous impervious membrane on the surface such that further oxidation or attack by other things that don't like aluminum cannot get through (of course unless you scratch the coating off). This is very much different from iron oxide (rust) which continues to allow oxygen through the outer layers so that an iron piece can rust all the way through.
In fact, aluminum oxide is such a good coating it creates one of the only flaws or drawbacks to anodizing.... the final coating thickness, by coating standards, is for the most part relatively thin. So you really can not get seriously thick aluminum oxide coatings. But on the other hand, aluminum oxide is a seriously strong (hard) compound and often used as an abrasive for many things from sand blasting to sand paper.
Rob Kress
Rob, Do you have an opinion whether, if these items are indeed anodized, that the coating of aluminum oxide would be enough to protect it from corrosive effects of the PT chenmicals?
I would assume that for it to be effective, they would have to anodize it after drilling the holes, right?
And - do you have an opinion about the cost for a piece of this, as marketed?.
Excellence is its own reward!
Piffin,
Hard to believe that anyone would ask my opinion on much but here goes.....
I have not been following this thread very closely but from what I have seen, I really like the idea of this metal bracket. I like it much better than just putting some washers under a ledger because, the majority of the strength of the ledger comes from the contact friction between the ledger and the member it is bolted to. When you put washers between the the ledger and supporting member, you essentially eliminate the contact friction (which really makes all the strength in the assembly) and create a bending moment on the bolts. So now you are totally, literally hanging on the bolts. Unless they are 316 stainless steel bolts, I think this is less than ideal. But you all know this anyway and I'm just covering old ground...... but giving my opinion.
So, I really like the idea of these brackets as they spread the load of the total bending moment over a larger surface area and a few bolts. Plus you get a little bit of contact friction which helps bring some more load strength to the whole assembly.
I would be surprised if these brackets were not anodized. Plain uncoated aluminum does not really hold up to much in heavy applications (outdoor, construction, machines, etc...). But, these brackets may have been an after thought...... for all we know, this manufacturer is the biggest heat sink maker on the planet and sells these I beam shaped extrusions to electronics folks for high heat load electronic equipment. Those cats certainly don't need to have anodized aluminum. So you can imagine these guys making this I beam extrusion and someone at the place says, "Hey, I've got a great application for these things that no one has thought of yet." And it goes from there. May also be the reason for lack of engineering data.
If they are anodized, then yes, drilling holes will completely void the integrity of the coating. And coating after drilling in not an option (too much money).
Is this piece expensive? I think so. If it were me and I was a serious deck guy, this is what I would do (of course depending on how many I do a year and or how I define "serious deck guy"). I would call my supplier of steel I beams (steel fabricator) and order these things by the piece out of steel I beam. If I was using 2 x 10 ledger I would order my pieces 9 inches long. I would have them drill the holes and then prime them. Doing it that way, these should cost under $10 each. Once I got them, I would paint with good exterior paint. And if that didn't work out well, then I would order them unpainted and send them out for powder coating (small batch powder coating is readily available and inexpensive because of all the crazy southern boys and their Nascar wannabe obsession.... also applies to northern Nascar wannabes too). And if that didn't work, I would pay more money and get these made in stainless. Aluminum would be my last choice cause it is just as expensive as stainless and harder to protect in the weather. Or if you like working with steel and have the right tools, you could order drops of I beams (the extra length that gets cut off from the 40 footer when someone orders a 26' 4 3/4" piece). These can be had for very cheap. Then just cut off with one of those abrasive metal chop saws and drill in a drill press. Easy enough but probably not field work. Of course then some sort of protective coating.
I have to confess to knowing absolutely nothing about the new PT lumber and corrosion effects but I will speak to another effect that may be an issue..... Lets say you get these fancy aluminum brackets and the new PT doesn't attack the anodizing. You still have to use steel or stainless steel bolts. And in the presence of an electrolytic solution (water and I'll bet this new PT stuff), you get galvanic corrosion between the two dissimilar metals (sorry if I am covering old ground anyone). Is this significant? Well, with significantly dissimilar metals or significant electrolytic solution, yes. What does it look like? Just like regular corrosion. So your bolts will fail right where they touch the aluminum bracket. Maybe one more reason to use steel or stainless.
There you have it. A little background about me..... I have a physics degree and worked as an engineer for 10 years. I also have 17 years of metal machining experience and worked for a machine shop that made custom metal bracketry for industrial actuation products.
So does that make my opinion worth much? I'm not really sure it does. Thanks for asking though.
Rob Kress
Rob, I thought the purpose of using SS was because of it's low reactivity in just about any hostile chemical environment. Same for galvanic reactions with dissimilar metals. We use SS to line the scrubbers in our power plants. The stuff last 10 to 15 years in a high sulfur dioxide and NOX environment. Surely the chemical treatment in the new PT lumber isn't that bad. I can't see how SS in contact with Al. would cause any adverse reaction.
Feel free to explain how I am wrong. I don't know that much about metalurgy. i am just trying to learn , so fir away. you won't hurt my feeling.
Dave
Dave,
I am certainly no expert either but essentially, the farther away two metals are from each other on the galvanic list, the more reactive they will be. Stainless, is really not an exception. It also reacts to galvanic corrosion, you just don't have the stuff around that causes it a lot of trouble (I used to do a lot of work with power plants and their scrubber applications..... actuated valves.... lots of them). Anyway, you should see how fast they run the stainless steel guy out of a salt mine. Brine and stainless for the most part are not swimming combinations. That's why every salt water marine application is brass or aluminum bronze.
So if you want to know a little more try starting here
http://www.eaa1000.av.org/technicl/corrosion/galvanic.htm
and then maybe do a more specific google search.
Hope that helps,
Rob Kress
Dave, you should also be aware that stainless, especially when used in corrosive applications, comes in may recipes,and special applications call for special formulations of SS.
SamT
thanks, There's a lot to think on there, but the steel looks better all the time.
I don't remember that they say that it is anoidized in the website for these. Something more like, "Special Magic Inti-corrosive coating" which would sound marketable to the DIY crowd.
One other thing I have been mulling over here -
Mike Maines mentioned that they were time consuming to use. I would presume that this is because of the need to line up holes in pre-bored brackets. In looking at composites, I think they would be easy to drill onsite so that one could mount to the wall first, then clamp the ledger to the mounts and drill in place, sliding a bolt into each hole as it is made..
Excellence is its own reward!
Piffin,
You used the word composite and it triggered something in my mind and I had an idea so I went looking. How about fiberglass reinforced plastic I-beam?
http://www.bedfordplastics.com/beams.htm
Everything one could ask for. High strength, corrosion resistance, and field friendly (I would think you could cut this with a regular miter saw). And I'm sure those cats above aren't the only people who make these things. Heck you could probably pick up a 16 ft piece or something at your nearest big city and just hack pieces off when you needed them. Then clamping and drilling in place would be easy as using wood (although I like that idea even if steel was being used).
You mention this method of deck ledgering being time consuming and I can understand but isn't that the point that every "fine home builder" has to consider on every project.... what is "fine" and when is it "fine enough". Doing things like this can only improve one's reputation as a "fine homebuilder". Is it worth it? I don't know cause I don't run my own show. But the next time my boss and I do a deck, this is definitely something that we'll discuss. We consider ourselves (we're a small operation of just the two of us) to be better than most of the other riff raff in old, broken down Chevy custom deluxes.
And isn't this the best part about web forums like breaktime. Discovering and discussing new and better ways of doing the things that we do every day.
Rob Kress
Yo!
Been a good discussion!.
Excellence is its own reward!
Rob, Many moons ago I worked in a shop that did plating. We anodized titanium hydraulic couplings for aircraft hydraulic systems. Anodized coating is incredibly tuff..we would have a test piece in the tank and pull it out to mic. it for thickness added. If you have to have a given thickness that would be easier to mic. then taking a coupling out and measuring it. We sandblasted off the test pc. tween runs in the bath. If I remember right it is not awfully expensive, in our case the Titanium was the big$ . We also nickel plated "load beams" big hooks at the end of sky crane cables..we would plate a single edge razor blade at the same time as a test for total plate thickness..used to wear'em around our necks..they'd never corrode as one druggie there noticed...
http://www.titaniumfinishing.com/
Thanks Rob. Interesting stuff...Matt
What about a stainless steel I-beam?
Ditto. Of course, if the Al bracket is 21 bucks, take a wild guess what some 304 SS is gonna run.
I never met a tool I didn't like!
Why not a steel I Beam and have it powder coated or galvanized. I buy steel at 49 cents a lb and thats canadian, approx .38 cents US. I know I could get that powder coated for about $8.00, have never had any galvanizing done.
I had the same thought.
another idear is from a catalouge I just got last night from a plastics supplier. Thyey have Composite/fibreglass I beam pieces, I think eight feet long for about $25. Again, the engineering is the big question..
Excellence is its own reward!
Some kind of hard to drill holes into!.
Excellence is its own reward!
Is there some way to counter act the corrosive effects, like using a sacrificial annode some where in the electrical path that causes the galvanic reaction between salts/copper/ aluminum?...I think that some ingredient is a sodium / salt in the preservative..cant blame it all on the copper.
Jus thinkin outta the box..
The problem with sacrificial anodes (similar to the rod in the electric water heaters) is that it eventually will be eaten away and need to be replaced.
The peel-n-stick solution is the one I would use, if I were to take the risk of using Al with the new PT lumber.
Whether or not the copper in the new PT lumber will attack a thicker piece of Al is uncertain, but I can't imagine why it would not; it would just take longer to degrade and eventually fail.
In a perfect world, the manufacturer would address the issue and an indepedent testing lab verify its claims. But I think actual use will provide the results and verifications, one way or the other. We just need to decide if it is worth the risk.
I never met a tool I didn't like!
Now ya REALLY got me thinkin. For my outdoor stuff, on an old log home, I will be using naturally resistant species. If the qualities of the natural compounds resist rot/bugs..what effect will those compounds have on Al. flashings? Nothing on the old place had any flashing to use as a "control". I see cut nails that are in Chestnut, Whiteoak, Locust still doing the job after 100+ years. I will be building the Veranda with Locust and W.O. and of course flashing to the existing..sandwiching al. flashing tween the joists and decking (which I am spiking down with cutnails)..White Oak=tannin, acidic..iron nails=ferrous, al. flashing makes a battery or something similar right?
I am guessing that the peel and stick you mentioned is used like a barrier...keep the flashing from contact with the new PT? I am sure that for new work (read, paying job for someone else) I will be using more traditional methods including the new pt, and SS fastners...HD galv. at the least.
Ahh..screw it..for my place I'll use the copper..just thinkin..
We used these when I helped build a house on Vinalhaven Island, Maine a few years ago. As I recall we spaced them about 6' apart, used SS fasteners, and doubled up the "ledger board" because it becomes a beam. The guy I was working for swears by them. I thought it was too much extra work and cost when more conventional methods will work (Membrane behind the ledger, space the ledger with a few washers).
How about just some good paint? Seems like all that is trying to be accomplished is to place a barrier between the alum. and the new pt lumber. A high quality coating might be all that is needed.
Dave
Maybe Dave, but with paint, you have to be sure it dries first. I always have scrap of bituthene or Vycor left in my truck.
The thing that bothers me qabout these things and the way they are marketed is that there is absolutely no engineering information available. Of course over half the builders in Maine wouldn't notice that anyway.
"whaddya think, Merle, will she hold?"
"Yep, Sam, Suppose she'll hold a dancing elephant. She's some solid there!"
"Ayah. I wouldn't hesitate to let my mother in law dance on that deck."
"Well, There you go, that settles it. That deck is as good as she comes."
but it would be nice to see some numbers as to how much load each piece can handle so that I could plan a large deck..
Excellence is its own reward!
Never saw the second item but I have used the first one. What I used to make those were some left over sections of guard rail supports normally used along the highway. The ones I used would have to have been called Massachusetts brackets. They were used for over 25 years along the road & were still like new. But it sure is a big labor saver to have someone else cut them.
Nice photos, a picture is worth a thousand words