When it comes to trusses "Piggyback" is a four letter word. Piggyback trusses are little trusses that sit upon larger trusses to allow the roof configuration to reach a certain height/span. In general a piggyback system is very expensive and time consuming to put together. Piggyback systems can cost anywhere from $800 to $1500 per house depending upon the configuration, and in many cases this waste can be eliminated.
Why are piggybacks needed? When a truss is taller than the lumber company can safely haul on the road that truss must be broken up into two trusses. The limit is anywhere from 12' to 14' tall depending upon local hauling restrictions. I have reviewed many truss packages for builders and have discovered more times than not that there are excess piggybacks that can be removed. Here is how you can check:
- Request truss drawings from your suppliers.
- Look at the profile drawings of the individual truss configurations.
- Note any truss that has a flat section at the top.
- Flat topped trusses are likely piggyback trusses.
- Find the corresponding capper and add up the total vertical height.
- Verify that height with local hauling restrictions.
- If total vertical height is above the hauling limit but is fairly close here are some things you can do:
- Drop pitch slightly to lower truss below limit.
- Reduce overhangs
- Check for special permitting that will allow a larger haul.
In one instance a builder was paying an extra $1,400 per house and it was discovered he could just pay for a $50 hauling permit and eliminate the piggybacks.
So check it out. You may be able to save some money, make your carpenters happy and cut down on cycle time.
Silly truss supplier - piggybacks are for kids.
If you would like to learn more about Lean Design at IBS, Scott Sedam and I are doing a presentation called "Design Lean for Huge Profits" on Wednesday morning from 10:00 to 11:30 in West 307C and D. We will be discussing ways to increase the marketability of your home designs and increase your profit margins. This will be an exciting and informative event - check it out.