Why are trusses being used in homes

[homeowner]

Seems that every new house I see being built today are using trusses for the roof. I dont understand the reasoning to that. Trusses are great for large commercial buildings and barns, because they eliminate the need for posts, but why are they being used on smaller homes, which have walls under them and eliminate the need for using a truss?

Three reasons come to mind to NOT use them.

1. More lumber is needed to make a truss
2. It costs more than just using lumber
3. There is no usable attic in those homes.

In stick built homes, the attic could be turned into a nice living space. You can not do that with a truss roof. So, the attic is useless other than a place to store stuff in between all the braces.

It just seems senseless to use them on a small home. Besides eliminating a useful attic, the cost to build would be significantly increased. Not just the cost to manufacture the trusses, but also the cost to install them, because a crane is needed to get them on top of the house, and a crew of men to install them. Framing a roof with plain dimentional lumber is so much easier, as well as cheaper and one gets a useful attic to boot..... One person can frame a roof by themselves and no crane is needed. WTF?

I have yet to find any GOOD reason to use them on a house!

[dpb]

...

Both of those are wrong and it's the "why"...as well as the time factor of not having to stick-build on site but simply set the truss in place.

--

[hrhofmann]

They permit the use of wide, unsupported areas on the main floor, which is necessary for the open concept homes that are currently in vogue

[clare]

Trusses use smaller lumber because the truss reduces unsupported spans and provides good bracing. Overall it can actually use LESS lumber - and at the very least, cheaper lumber.

[gfretwell]

Trusses come with engineering that you need in a lot of places They also require a lot less on site carpenter skill and lower labor cost. I wouldn't bet most of the kids today could cut a rafter. They are much faster to do. I am not even sure they use more lumber since trusses are 2x4s and rafters are usually 2x6 or 2x8s with 2x6 joists.

The crane is chump change compared to the labor of laying out, cutting and setting rafters.

[Tony Hwang]

Hi, Almost all houses built today is pretty well assembling prefab trusses, walls, staircase, railing, cabinets, windows, etc. you name it. Simply law of economics. You can still have a post and beam custom house if you want. It will cost more and take longer to finish.

[clare]

Up here in Canada most houses are still built "on-site" but the VAST majority use pre-engineered trusses for the roof - and quite a few use manufactured floor joists as well (plywood or aspenite web with 2X4 or

2X3 lomber cap strips. All about not requiring "old growth" lumber (2X8 and larger dimensional lumber)

[Doug]

Aside from the other replies I read, I'd say overall better workmanship and more uniformity in measurements.

[Tim Watts]

My English house, built in the 1950's uses 2x4 rafters with purlins at the halfway point - and a centre load bearing wall. Hardly extravagent with timber volumes.

Mind you, timber was better back then - I can walk on the old ceiling rafters with no noticeable deflection over a 3.8m span.

Trusses are cheap in that they are banged out at the factory and need little skill onsite, other than a bloke who can space them evenly and nailgun a few diagonal braces across them to keep them upright.

But I agree - hideous things. Any future loft conversion involves rediculous amounts of work.

[Tim Watts]

I think that is just a sign of modern builders being lazy or incompetant.

My house (1950's) has excellent regularity in the original framing work. Unlike the loft conversion that was done in the 1970's by a moron with a hammer.

[Hench]

In Halton I notice alot of floor joists made from engineered plywood but I don't always see caps on/in them. Seen this in a couple of over million dollar homes from the basement side. Maybe I missed the caps.

Owners of over million dollar house don't like a common man studying new construction techniques of their homes too closely...

[Hench]

New housing has become a volume business. Build dozens if not hundreds of houses at one time using methods that a car manufacturer or a fast food restaurant would use...

[Art Todesco]

In all the replies this was not mentioned. With trusses, heating ducts, etc. can be run perpendicular to the truss itself ... not so with solid joists. This makes the room below without bulkheads to house that stuff. In my house it uses trusses over the basement. The basement ceiling is totally flat. So if someone wanted to finish a basement room, it would work out well.

[Doug]

I'm not surprised and I was referring to more modern housing. I've seen some modern wood construction in home building that made me glad I wasn't buying that home. I also know a good carpenter that almost got fired because he couldn't make a quota on hanging front doors and it wasn't due to lack of knowledge. Personally I love really old homes circa early 1900s tho I do recognize that some aspects of construction have improved, if DONE PROPERLY.

[Tim Watts]

On Thursday 03 January 2013 13:23 Art Todesco wrote in alt.home.repair:

Did you mean "engineered joists" rather that "trusses" which implies "roof trusses"?

[Bill Gill]

But how many homes built in the early 1900s are still around? It is true that the ones that are still around were well built, but the ones that aren't around may have been poorly built. You have to figure out what the average was. I'm sure that there were homes built back then that were junk from the start particularly small homes. When I was young we were renters and we lived in some houses that were basically shacks with pretensions. You haven't lived until you have lived in a house with single wall construction. The only thing keeping out the wind is the wall paper.

Bill Gill

[Pat]

If by lazy, you mean being able to build a quality product for less money, then yes. Modern trusses are mass produced. The material and labor to install them is less, not more. And, yes, as someone else said, the installation is more like to go smoothly even if some of the workers are "incompetant" as you say.

[willshak]

[e-mail] wrote the following on 1/2/2013 8:34 PM (ET):

Stick built roofs require at least 2" by 6" lumber. Trusses are usually 2" x 4"s for general housing. There may be more lumber, but it is smaller lumber.

1. It may require a crane to lift the trusses, or more workers for low roofs.

[TomC]

[e-mail] wrote in news:j9n9e8h2ntua6pro7k3k2rh1kdl4ro3ndh@

4ax.com:

There is no usable attic in todays homes because the insulation reguirements of 12" to 20"(R30-40)far exceed truss dimensions. Framing for usable attic space to accomodate the insulation would be cost prohibitive.

[Tomsic]

- SNIP-

Agree. The "local workmanship" around here framed our house thinking that somehow we wanted garage doors that were only 3 feet high. After the builder fixed that -- wasting time and a lot of wood, I was glad to see the prefabricated trusses and other structural parts arrive.

I'll throw in another reason to use prefab trusses as well. As I visited several "independent living" retirement communities with a relative contemplating moving into one with detached homes, we were surprised to find the management very willing, at no extra charge, to tear out walls and partitions to suit whatever living style was wanted. The single-story homes had no attics and with truss construction could be remodeled easily into different floor plans including one large kitchen-dining-living room. Some units were being changed every 5 years or so.

Tomsic