Truss question

[james glenn]

+1 for Mark's input.

I am an architect, and that is pretty much what I would do. Call a local truss manufacturer and give them the details. They will size the LVL or gluelam or whatever you want to use for you, as long as you buy the beam from them.

But the trusses def. are not built for clear span, so do not take that wall down until you have them supported.

[Erik France]

End of the day, I started this thread hoping that everyone would overwhelmingly say "no problem! knock that wall down". Since it's not my building, I don't htink I want to drop a couple thousand bucks putting in footings and LVL's. That would definitely be the right way to do it, but the shop is functional (albeit a little awkward) the way it's set up right now.

Thanks again for the great discussion and feedback.

Like Mark said, you probably wouldn't have to spend a couple thousand. With the existing construction being 2x4s the ceiling and roof isn't designed for heavy loads, probably just the minimum dead and live loads. LVLs will give you greater opening spans, but you should be able to do at least a 12' opening with 2 or 3 2x10s. The posts and footings won't need to be all that big either.

Most decent lumber yards will have an engineer on staff, a truss manufacturer will certainly have one. You could probably get by without having to hire one yourself outright.

[John P Clark]

As a professional engineer (PE) that has designed numerous structures and a General Contractor for 30 years, all of you are tempting fate with your responses. I do not know many lumber yards that are willing to "size structural members" and take the liability. In addition to the beam, you will need posts, and a good foundation to support the posts. A couple of “blocks” is not a good foundation, and without knowing the loads, soils conditions, framing configuration, it is impossible to determine this. My suggestions if you really want to do this, do the proper thing and find a PE in the area that is familiar with structures and consult with him. You may spend a little additional money going this route, but the structure should not fail and you will not have to explain to your father’s insurance company why you did this without a permit or consulting an expert. My two cents worth

[Peter Aeschliman]

As a professional engineer (PE) that has designed numerous structures and a General Contractor for 30 years, all of you are tempting fate with your responses. I do not know many lumber yards that are willing to "size structural members" and take the liability. In addition to the beam, you will need posts, and a good foundation to support the posts. A couple of “blocks” is not a good foundation, and without knowing the loads, soils conditions, framing configuration, it is impossible to determine this. My suggestions if you really want to do this, do the proper thing and find a PE in the area that is familiar with structures and consult with him. You may spend a little additional money going this route, but the structure should not fail and you will not have to explain to your father’s insurance company why you did this without a permit or consulting an expert. My two cents worth

You're right. I'm quite risk averse by nature, so I would never undertake a project like this without professional help... which is why I won't undertake this project at all. Not worth the risks or the money. The shop works fine as is.

Thanks again everyone for an interesting discussion. This project isn't going to happen, so I don't want to waste any more of your time.

Thanks!

Peter

[Mark Bolton]

As a professional engineer (PE) that has designed numerous structures and a General Contractor for 30 years, all of you are tempting fate with your responses.

Well with all do respect John, and I do respect your profession, lumberyards and GP, TJI, Advantec, Truss Manufacturers, and the like, ALL do call-outs for simple situations like this on a daily basis. We have even had very complex call-outs done numerous times. While I have no firm tally would probably guess I have had a number in the hundreds done personally by TJI and GP directly or their authorized designers and distributors. Most recently GP spec'd all girder, joist, and rafter spans for a project we are completing at the moment.

Simple spans like this (and this is by all means a simple span) are just that, simple. While it would be nice to enjoy the luxury of calling in a structural engineer, a soils engineer, and an architect, and paying their respective fee's to increase a window opening from 3' to 10' it just cant happen that way in the real world. Adding 2-4 footings (if they are even needed depending on how load bearing wall is supported currently) and a pair of LVL's down the center of a building is a call-out virtually every lumberyard we have dealt with can handle in a matter of 30 minutes sitting at a desk to 2-3 hours for a return phone call. The call-out comes with a print based on the project details submitted and is clearly noted what is covered and what is not.

We by all means call in an engineer when anything is beyond a simple span and have done it many many times. The problem lies when you get in certain locales and you have some simple engineering you need done and any engineer you talk to wants 1500-2500 dollars for their stamp. That just aint gonna cut it on a small project. In our old location we had a great engineer who would do a small project or even a slightly complex project for 300-500 dollars max. Give us a stamped drawing to satisfy the building department, and we were all happy. Where we are now that just doesn't exist. Thankfully we haven't been in need for a while.

Again, I completely understand your position and your motivations but the simple fact of the matter is opening up a load bearing wall, which is all this is, is not a defacto situation to call in an engineer in my opinion. The residential building industry would grind to a halt if we were forced to go that route every time we opened up a span.

Mark

[John P Clark]

Just looked at a house that the current owner hired "a contractor" that did some work on his ceilings and in the process removed structural elements from the roof. No permit, inspection and now he is looking at 15 to $20 k to fix it on order to sell it. I know that you think this is simple but the sometimes there are items that appear "simple" but might not be. Remember, the tables in the IRC and by TJI etc are for "typical" loading conditions which is not always the case

[Henry Ambrose]

I agree with Mark and John, even though they seem on opposite sides. Mark (or I) would look this over carefully and do it. It'd be over in a few part days. But Mark's not there and I'm not there. So listen to John.

If you call around you can find an engineer who can solve this problem for you and not charge too much. Ask at the good lumber yard you frequent.

Call up a couple of engineering companies. I found a guy once who was retired, had worked there for 30 years by doing that. He had a "retirement business" consulting and was happy to come out and have a look. I was almost embarassed to pay as little as I did for a great drawing and precise instructions including order of steps and techniques. Job went great.

[Mark Bolton]

I was almost embarassed to pay as little as I did for a great drawing and precise instructions including order of steps and techniques. Job went great.

Sounds like we may have had the same guy!!

I agree, and its beyond the project stage as the OP has stated its not going forward period. Your statement about not being there is the most pertinent one out there. My point is that on the internet you generally get two perspectives,

1. your going to die.
and
2. yeah go ahead dont worry about it.

When the fact is the vast majority of things land right in the middle of the two and with some sound sense and reasoning the individual can figure out if they are capable and willing to figure it out. You are of course going to get the chicken littles who believe they will in fact die, and the fools who will storm ahead with wreckless abandon. They are the chaff, the people in the middle are the wheat.

We all can find "holmes on holmes" stories, I have thousands,...

Mark

[Thomas Canfield]

Peter,

I did not see any mention above about the installation of ceiling material on 2x4 "joists". The span allowed would be much less than the span you indicate. The original truss system was probably designed (built) for only the roof sheeting loads. You may have other questions to answer in your search. More confusion for you.

[Peter Aeschliman]

point is that on the internet you generally get two perspectives,

1. your going to die.
and
2. yeah go ahead dont worry about it.

That was funny. Almost spit out my morning coffee.

You guys opened my eyes to the complexities of this project. I may look into this again when I'm willing to spend the money to hire somebody to do the work (or at least to do the design).

In the end, I only really need a 50-60" opening. The only place where this wall is inconvenient is where it's next to my table saw. I want to be able to cross cut wider panels on my excalibur sliding table... so I may be able to get away with something simpler... I'm picturing some framing much like when you put in a header for a new window.

While I'm at it, a 3-4' section of the bottom plate of that wall is partially rotted due to a burst pipe many years before I inherited the space... so I'd have to replace the bottom plate while I was at it. Back when they built the barn (early 70's) they didn't use pressure treated lumber for the bottom plate.

Anyway, thanks again guys for your help.

[Henry Ambrose]

In the end, I only really need a 50-60" opening. The only place where this wall is inconvenient is where it's next to my table saw. I want to be able to cross cut wider panels on my excalibur sliding table... so I may be able to get away with something simpler... I'm picturing some framing much like when you put in a header for a new window.

Well this fits into the "do it and don't worry about it" category.
Build a header from some 2X12s, add support on each end and have a nice 6' wide opening. You're just making a big door opening - read up on how to do it if you have doubts.

Disclaimer: You're gonna die if you do it wrong.

[Phil Maddox]

If you've drawn that accurately, the center wall in your shop is a load bearing one. A "standard" truss has a "W" in the middle, spreading the load out to the outside walls. the one you have shifts the weight to the center wall, just like hand framing might do. Something that is gang nailed, whatever that is, was probably site erected. Any stamps on the truss?[IMG]file:///C:/Users/PHILIP%7E1/AppData/Local/Temp/moz-screenshot-4.png[/IMG]

[Peter Aeschliman]

Well this fits into the "do it and don't worry about it" category.
Build a header from some 2X12s, add support on each end and have a nice 6' wide opening. You're just making a big door opening - read up on how to do it if you have doubts.

Disclaimer: You're gonna die if you do it wrong.

Ha ha

Yeah, I've been doing a little reading on the subject. It actually looks pretty simple. My only concern of course is adding temporary supports while I do the work. But I'm sure I can jerry rig something so that each truss is supported on each side.

If you've drawn that accurately, the center wall in your shop is a load bearing one. A "standard" truss has a "W" in the middle, spreading the load out to the outside walls. the one you have shifts the weight to the center wall, just like hand framing might do. Something that is gang nailed, whatever that is, was probably site erected. Any stamps on the truss?[IMG]file:///C:/Users/PHILIP%7E1/AppData/Local/Temp/moz-screenshot-4.png[/IMG]

Yeah, the truss in my garage (much wider span than this would be if I removed the wall) has two key design differences: The web pieces form a "W", and the bottom chord is one continuous piece.

Gang nails are these things:

http://www.google.com/imgres?imgurl=...1t:429,r:0,s:0

I'd have to rip out some drywall to see if there are any stamps... but at this point it's pretty clear the trusses were built on site and never designed to span the entire width of the building.

[Mark Bolton]

There is no need to "jerry rig". You just build a temporary wall on either side of the opening. Its a simple as tacking a 2x4 top plate to the underside of the truss on both sides of the opening you propose. Then another plate on the ground/floor below, then 2x4 studs directly under each truss between the two plates. Its just building a temporary support wall outbound of the opening to be created. This carries the load while you remove the section of the load bearing wall and replace it with your header and posts.

If the stud length is long (between floor and truss) you can strong back your 2x's by nailing a second on to each forming an "L" shaped stud. This will stop them from bowing under load. Alternately you can diagonal brace them down to the bottom plate to achieve the same thing.

Really no big deal, but you are still probably going to die (someday). But at least you'll be happier in your shop til' you do.

Mark

[Mark Bolton]

http://www.rd.com/images/tfhimport/2...e003img001.jpg