I am going to be building a carport in the style of a big pergula. Flat roof, 20′ x x 30′. For the main beams, an architect friend suggested Paralam beams.
Paralam, glulam, LVL, LSL. For an exterior project like this, is one better than the other? Appearance is not important as the entire project gets wrapped in WRC to match a residing of the house.
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How much of a snow load do we need to consider?
I live right outside of Chicago, so we get considerable snow.
I realize I need to factor snow load, dead load, etc into the engineering to deterrmine beam size. That will eventually be determined by an engineer in our family.
I am kinda wondering if one type of engineered bean has advantages over the other. Given the large span of this between supporting columns (25'), there is going to be a considerable load on the two main beams that support the roof.
Edited 2/12/2004 7:37:14 PM ET by pino
It is a matter of weighting the variables of sizing for loads, cost, availability, and ease of installation. For instance, with small crew or difficult to reach locations, sistrering several smaller LVLs is better than one glulam. Other times, one product might be in satock in standard sizes while another might take three weeks to special order.
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I will have access to a crane for install. I am not so worried about delivery times as I am a homeowner doing the work with help of qualified family and friends.
i guess my concern is two fold.
First, what will give me the greatest load capacity with the lighest weight? Given the flat roof and span between the four supports, it seems like minimizing dead load is important. I will concede though that this determination will be the job of the engineer spec'ing this for me.
The other issue is that these will be outside. While I will wrap them with WRC they will still be out in the heat and cold of the Chicago weather. I didn't know if one product was better suited to exterior use.
If weather is the important concern, ypou can get PSL in PT but I don't see that as necessary.I doubt it will eversee a drop of water after constructed.
have engineerspec it two ways and then compare prices. That's what I do anyway. For me it is one visit because the lumnberyard has the software for the various products. Fiften minutes in his office and I've mademy decision.
Most often it is LVLs. Occasionally, Parralam.
For you, my instinct says parralam
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I live right outside of Chicago, so we get considerable snow.
Well then ... a large flat roof is definitely the best choice!
JeffBuck Construction Pittsburgh,PA
Artistry in Carpentry
your sarcasm is well taken.
However, the flat roof is an asthetic decision. The car port will have the look of a large pergola, with exposed rafter tails and a great deal of detail. The space will also be used for entertaining with an outdoor rock-face block fireplace built into the adjoining mud room. The whole thing fits into the arts & crafts look of the bungalow we are renovating.
believe me, practicality has nothing to do with this project.
Edited 2/12/2004 10:13:07 PM ET by pino
Pino, they're all made with waterproof glue. They should be protected from the weather, but heat cycles won't cause failure.
Fine Homebuilding reviewed engineered lumber in #150. I can't recall offhand the strength characteristics of each type, and my issue is packed away...sorry.
Regards,
Tim Ruttan