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Which type of roof construction is better....

Last Post 30 Sep 2009 07:38 AM by Rio. 9 Replies.

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rykertest

Basic Member

Posts:202

26 Sep 2009 10:32 AM
Engineered Truss or hand built? What I mean by hand built is hand nailed, done with proper sized beams, etc. and NOT an economy roof. I am having a on going conversation with a few builders I use and while I think engineered roof systems can be very strong, I still lean, ever so slightly, towards a well built hand nailed roof. IMHO, a hand nailed roof, with the proper wind ties, glued decking and some nice spray foam insulation underneath is about as strong as one can get before going to a concrete roof. Maybe sips would be stronger but that along with concrete is quite cost prohibitive. What has been your guys experience? What has your experience shown you to be true? Compare cost and all that to make it an apples to apples conversation.

wes

Advanced Member

Posts:810

28 Sep 2009 07:35 AM
While we each have our own experiences to draw on, and so our reactions, therefore, can be different, my first reaction to your belief that hand built rafter systems are better than pre-engineered trusses is: "ARE YOU NUTS?" Yes, I have used both methods many times over the years, and I have success with both, and problems with both. However, the truss systems are far more reliable from a quality point of view. This is more true today than 20-30 years ago. The quality of lumber is making it harder and harder to built stable roof systems. And stability is a very good thing in builting long term quality. I am sure that in many cases, it is cheaper to build rafters rather than use trusses, but the costs of callbacks can be killers to long term budgets.

Wes Shelby<br>Design Systems Group<br>Murray KY<br>[email protected]

Rio

New Member

Posts:80

28 Sep 2009 08:41 AM
Cost wise trusses usually are cheaper because they go up so fast and they also can span longer spaces but they do have drawbacks. A lot of people like to store stuff in their attics and with trusses that is a no no, so you can lose a lot of potential storage space. I've seen a company advertising garage clean up systems that hang off of the ceiling and I keep wondering when the first collapse of a trussed garage roof/ceiling assembly is going to occur as a result. We did a tour of a truss yard of one of the largest lumber companies on the west coast a few years back and were talking with the supervisor of the yard, a really nice guy, and he brought up one of his worries with trusses. He pointed out that with computer engineering it is possible to make large trusses with smaller components and then put concrete or clay tile on top of these 'optimally engineered' trusses. Then when the drywall is getting ready to be put up, especially on higher end homes, the contractor will shave the bottom chord to make sure there aren't any waves in the ceiling. His concern was everything getting closer and closer to the edge, structurally speaking, and he said he wondered how long before one of these overloaded assemblies came crashing down. It's been years since this conversation and I haven't heard of any collapses so maybe his fears were ungrounded. On the other hand we haven't had an earthquake of any significance since that conversation either. If spans are not an issue I prefer hand built conventional roof and ceiling assemblies because of the storage factor and also because the rafter tails are larger and also because I like to frame but spans usually are an issue as well as cost and boy, trusses go up fast, as long as a crane can be used to help place them.

rykertest

Basic Member

Posts:202

28 Sep 2009 09:17 AM
Posted By wes on 09/28/2009 7:35 AM While we each have our own experiences to draw on, and so our reactions, therefore, can be different, my first reaction to your belief that hand built rafter systems are better than pre-engineered trusses is: "ARE YOU NUTS?" Yes, I have used both methods many times over the years, and I have success with both, and problems with both. However, the truss systems are far more reliable from a quality point of view. This is more true today than 20-30 years ago. The quality of lumber is making it harder and harder to built stable roof systems. And stability is a very good thing in builting long term quality. I am sure that in many cases, it is cheaper to build rafters rather than use trusses, but the costs of callbacks can be killers to long term budgets. Tell me, what good comes from calling me "nuts"? Does it make you feel better to insult? Does this type of reply provide any benefit to the conversation at hand? Did your mommy and daddy never instruct you on how to disagree with any sort of respect? This type of approach serves no purpose but to boost your own self esteem, drives a wedge into a potentialy constructive conversation, and I will no longer read or reply to your posts. Grown up and learn how to have a conversation, even a disagreement like an adult.

rykertest

Basic Member

Posts:202

28 Sep 2009 09:20 AM
Posted By Rio on 09/28/2009 8:41 AM Cost wise trusses usually are cheaper because they go up so fast and they also can span longer spaces but they do have drawbacks. A lot of people like to store stuff in their attics and with trusses that is a no no, so you can lose a lot of potential storage space. I've seen a company advertising garage clean up systems that hang off of the ceiling and I keep wondering when the first collapse of a trussed garage roof/ceiling assembly is going to occur as a result. We did a tour of a truss yard of one of the largest lumber companies on the west coast a few years back and were talking with the supervisor of the yard, a really nice guy, and he brought up one of his worries with trusses. He pointed out that with computer engineering it is possible to make large trusses with smaller components and then put concrete or clay tile on top of these 'optimally engineered' trusses. Then when the drywall is getting ready to be put up, especially on higher end homes, the contractor will shave the bottom chord to make sure there aren't any waves in the ceiling. His concern was everything getting closer and closer to the edge, structurally speaking, and he said he wondered how long before one of these overloaded assemblies came crashing down. It's been years since this conversation and I haven't heard of any collapses so maybe his fears were ungrounded. On the other hand we haven't had an earthquake of any significance since that conversation either. If spans are not an issue I prefer hand built conventional roof and ceiling assemblies because of the storage factor and also because the rafter tails are larger and also because I like to frame but spans usually are an issue as well as cost and boy, trusses go up fast, as long as a crane can be used to help place them. Rio thanks for the reply. The speed factor is a big advantage with truss systems, that can't be denied. I think you hit on why I slightly lean towards traditional built and thats wood size. What are your thoughts on the plates used on truss systems? Do you feel they are stronger than conventional methods? Thanks again.

rykertest

Basic Member

Posts:202

28 Sep 2009 10:33 AM
Posted By Rio on 09/28/2009 8:41 AM Cost wise trusses usually are cheaper because they go up so fast and they also can span longer spaces but they do have drawbacks. A lot of people like to store stuff in their attics and with trusses that is a no no, so you can lose a lot of potential storage space. I've seen a company advertising garage clean up systems that hang off of the ceiling and I keep wondering when the first collapse of a trussed garage roof/ceiling assembly is going to occur as a result. We did a tour of a truss yard of one of the largest lumber companies on the west coast a few years back and were talking with the supervisor of the yard, a really nice guy, and he brought up one of his worries with trusses. He pointed out that with computer engineering it is possible to make large trusses with smaller components and then put concrete or clay tile on top of these 'optimally engineered' trusses. Then when the drywall is getting ready to be put up, especially on higher end homes, the contractor will shave the bottom chord to make sure there aren't any waves in the ceiling. His concern was everything getting closer and closer to the edge, structurally speaking, and he said he wondered how long before one of these overloaded assemblies came crashing down. It's been years since this conversation and I haven't heard of any collapses so maybe his fears were ungrounded. On the other hand we haven't had an earthquake of any significance since that conversation either. If spans are not an issue I prefer hand built conventional roof and ceiling assemblies because of the storage factor and also because the rafter tails are larger and also because I like to frame but spans usually are an issue as well as cost and boy, trusses go up fast, as long as a crane can be used to help place them. Rio I reread your post and wanted to comment on something else you said I thought was important. The tolerances of building in general is getting so specific, things are being built TO code as opposed to over code. Whats the minimum we can do to get the job done. Thats not the same to me as doing it right or better. It's like when I was younger, if I was on time, I was late. The same applies to building in my mind. If it's done to meet the minimum standards, it's not adequate. Acknowledging the point of diminishing returns, I would rather overbuild.

wes

Advanced Member

Posts:810

28 Sep 2009 01:54 PM
My "nuts" comment was made with a smile on my face. I expected some sort of snide comment in reply. I did not expect you to sull up and act like an old maid school teacher. You asked for opinions and I gave you mine. My experiences have led me to believe that one would have to 'nuts' to use rafters when trusses could be used. Your reaction would tend to indicate either a fragile ego or an exagerated sense of self worth. In either case, I'm sorry.

Wes Shelby<br>Design Systems Group<br>Murray KY<br>[email protected]

Rio

New Member

Posts:80

28 Sep 2009 07:43 PM
Rykertest wrote: "Rio I reread your post and wanted to comment on something else you said I thought was important. The tolerances of building in general is getting so specific, things are being built TO code as opposed to over code. Whats the minimum we can do to get the job done. Thats not the same to me as doing it right or better. It's like when I was younger, if I was on time, I was late. The same applies to building in my mind. If it's done to meet the minimum standards, it's not adequate. Acknowledging the point of diminishing returns, I would rather overbuild." I think if one builds to the minimum allowed by the various codes it will be adequate but I do prefer to overbuild at times. I like a stiff floor and never use the maximum span allowed by the span tables, we usually use 3/4" T&G subflooring instead of 5/8"; of course now they are selling the next size down on both of those, thereby saving the manufacturers 1/32" on each sheet which adds up I guess. I had an interesting experience years ago on a project I designed and did the construction on. We had a retaining wall tied into the slab and the engineer who worked with me on the design had called out for a 12" wide retaining wall with a lot of #5 rebar (I forget the exact schedule). The dude across the street was a building designer and while talking to the homeowner pointed out that the steel schedule and size was beefier than called for by code and the concrete wall only had to be 8". The owner came to me and started bitching about it and I told him I'd talk to the engineer and get back to him. I talked to my engineer, who is a very talented engineer and a person I have a lot of respect for and asked him if what the owner was told was true and if so why did he do it? He looked at me and said, "Rio, the one place you don't want to skimp is on the foundation. For the little bit more of extra cost of concrete and steel it's nice to be able to sleep easy at night. Also if anything does happen we can point out we went beyond what was called for". Living in earthquake country this was reassuring news and made a lot of sense to me. The next day I told the client about my conversation and he nodded his head and said, "I'm glad I picked you and not the guy across the street". BTW he was right about the added cost also. We ended up using 27 yards of concrete on that job and spent a lot of time making the forms for the concrete which reached almost 4' high in places (a lot of bracing for those heights). When you factor in labor, material and other costs the extra 'crete and steel was a pittance.

greentree

Advanced Member

Posts:587

30 Sep 2009 07:07 AM
Posted By Rio on 09/28/2009 8:41 AM Cost wise trusses usually are cheaper because they go up so fast and they also can span longer spaces but they do have drawbacks. A lot of people like to store stuff in their attics and with trusses that is a no no, so you can lose a lot of potential storage space. I've seen a company advertising garage clean up systems that hang off of the ceiling and I keep wondering when the first collapse of a trussed garage roof/ceiling assembly is going to occur as a result. We did a tour of a truss yard of one of the largest lumber companies on the west coast a few years back and were talking with the supervisor of the yard, a really nice guy, and he brought up one of his worries with trusses. He pointed out that with computer engineering it is possible to make large trusses with smaller components and then put concrete or clay tile on top of these 'optimally engineered' trusses. Then when the drywall is getting ready to be put up, especially on higher end homes, the contractor will shave the bottom chord to make sure there aren't any waves in the ceiling. His concern was everything getting closer and closer to the edge, structurally speaking, and he said he wondered how long before one of these overloaded assemblies came crashing down. It's been years since this conversation and I haven't heard of any collapses so maybe his fears were ungrounded. On the other hand we haven't had an earthquake of any significance since that conversation either. If spans are not an issue I prefer hand built conventional roof and ceiling assemblies because of the storage factor and also because the rafter tails are larger and also because I like to frame but spans usually are an issue as well as cost and boy, trusses go up fast, as long as a crane can be used to help place them. Rio, I would have to disagree. You can have a truss' engineered to do what you want. They will build them to accept a tile roof, attic storage, whatever live and dead load you want. You can have a storage room put into your trusses if you want, tray ceilings, different roof styles. I've gone to a truss makers yearly show and was blown away by what they can do, it's amazing really. A crane is not really necessary either in alot of cases. 2 guys can bring trusses up on ladders, for me up to around a 24' 5/12 or 6/12 before it gets uncomfortale. On 1 stories I've used a skidsteer with a boom attachment, you can use a telehandler with a truss boom and using steering modes and frame tilt you can quickly and safely drop trusses spot on. Costs alot less, doesnt take much longer and you have a valuable machine on site.

Rio

New Member

Posts:80

30 Sep 2009 07:38 AM
Those are all good points. When I was referring to the truss yard and the conversation the trusses the supervisor was referring to were for high end tile roof houses. I guess the contractors wanted to save as much money as possible by cutting it as fine as possible. On the various truss configurations you're right that one can do just about anything with a truss, if one is willing to pay the added cost. I've found the biggest drawback to doing conventional roof framing is having a competent crew leader that really knows how to cut a roof. If you have a dude or Betty who knows that (not too many Betty's are in that field, LOL) it can really go fast and come out tight. Speaking of tight a lot of the work I have done in construction has been infill and sometimes there is no way to get any sort of machinery and a truss to where the truss is going to placed on the roof which is something that the unwary contractor can get bit in the rump by if not planning ahead (unfortunately I have some scars in that area).