- Head off common problems and errors
- Avoid costly repairs and delays
- Shoot for a smooth roof stack
It definitely can be quite amazing to watch a skilled stacking crew tilt up a set of roof trusses, and blow through an entire home in two or three days. It also makes it real easy to see how an engineered roof system like this can cut both time and payroll expenses on your home building project.
Not a Lot of Room for Error
There is one glaring aspect that the average onlooker doesn’t see though, and that is that engineered roof systems leave little if any room for adaptations if anything isn’t just as it should be. Now with conventional cut and stacked roofs, adaptations are quite common place, and accepted.
Problems With Trusses Suck!
So even a small problem with just one truss can shut the whole project down, if its a main hip or girder truss. Then needless to say, dragging problem roof trusses off the roof to be trucked away and repaired can take a good whack out of your pocketbook, and your motivation factor.
It’s Hard to Get things Right the First Time
So the best thing, is to understand from the start that those guys you saw who were blowing out roofs on the housing tract have most likely been doing the same three roof styles for the past year. They worked out all the little glitches months back and are now on a roll.
You Have One Shot to Get it Right
You on the other hand, have but one shot to get it right, and that means that you have to get in front of any and all screw ups, and block them before that happen. The good news though is that this is entirely possible, but it sure helps to know where to expect problems, and to know what preventative measures to take.
The First Mistake You Can Make
The very first mistake you can make, is to assume that by going with an engineered system the job of constructing your roof will always be made easier. Now for the majority of cases this is in fact true, but on more complex roofs, you might better served by going with a conventional cut and stacked system.
Don’t Be Deluded By the Concept
Don’t kid yourself. If you have a large, steep complex roof with lots of hips and valleys, you’re in for a bunch of work either way. Then if you toss in some long vaulted ceilings, and perhaps a dormer or turret or two, someone is going to have to set up some saw horses and cut a bunch of rafters anyway too.
Your Trusses Have to Be Ordered Weeks Ahead of Time
Now the first thing you’re going to need to do, once you make the decision to go with roof trusses, is work out your scheduling. You see, the trusses have to be plunked down on top of your finished frame, which means that you have to synchronize your frame work in such a way that it’s all done a few days before your trusses arrive.
Delays Can Lead to Costly Problems
If that all sounds easy, it’s not. This is because if there’s any problems that hold up your framing then all that can lead to your trusses arriving for delivery, and you having nowhere to put them. Of course they’ll find some place to stick them, and then charge you a bundle to come back and load them on your frame when it’s done.
It’s Time to Start Looking Around
So now that you have your job scheduled perfectly, such that there’s not going to be any truss delivery nightmares, it’s time to start back looking at other areas, to work on catching any and all actual “wood and nails” problems before they can pop up and bite you on the butt.
Deviations in Your Foundation Transfer All the Way Up
It’s a whole heck of a lot easier to pull a few nails than it is to jackhammer out concrete. What this means, is that you need to stay on the ball as the forms for your foundation are being set up. Now this doesn’t mean that you need to make a nuisance of yourself.
Check the Outside to Outside Wall Measurements
Simply bring an extra set of hands to the job site on the afternoon that the forms are finished being braced off, and pull the outside to outside measurements. Those would be the overall “north to south” and “east to west” measurements on the entire building to compare with the dimensions on the plans.
You’re Looking for Big Mistakes of an Inch or More
Deviations of up to ¾ inch are acceptable. Remember you’re not looking for perfection because even your roof trusses will have some slight size variations. Rather, what your looking for is “big mistakes” over an inch that can lead to big problems. Remember that the trusses are being built off your plans, so the house has to match.
Roof Trusses Can Ride Over Certain Deviations
Now as it pertains to deviations in the overall size of your foundation, lesser lengths are better than larger lengths. What this means, is that if your foundation ends up an inch too small, that’s a heck of a lot better than it being an inch too big. Roof trusses can ride over shortage problems but if the frame is too big they hang up on their tails.
How to Check the Poured Slab
So assuming that all is OK with your forms, and the foundation gets poured, then after the forms are removed you have to check it again. This time though, you need to check it for a hump in the middle. Foundations are supposed to be level but just the same, minor dips and humps here and there are to be expected.
A Hump Up Over a Half Inch Can Be a Problem
What you don’t want to see, is “major hump” in the middle that’s going to get in the way of the trusses riding across the home. So use a very tight string, pulled across the floor from end to end, to check for a hump that’s over a half inch. Deviations up around an inch or more are a problem that you’re going to have to deal with before your roof trusses arrive.
Two Ways to Frame Around a Hump
There are two ways to deal with large humps in a slab foundation, and one of them is to simply leave the walls out of the frame job, and stick frame them up to fit after the roof trusses are installed. The other fix is to use a string to determine the height of the hump, and simply trim it off the studs as the walls in the hump area are framed in.
Double Check and Brace Off Your Plumb & Line
So assuming that your walls are up, and the house is plumb and lined, then it’s off to locate the next problem area before your roof trusses arrive on the scene. The place to look is your outside walls. Make sure that they’re lined up “straight” and braced off “well”. Once the trusses are dropped on top of your walls, you’re going to be stuck with any deviations. Brace them off good!
Your Roof Trusses are Here!!
OK. You’ve made it this far, and now your trusses are on the truck coming up the driveway. So does this mean that you can start to relax? Not at all because there is still plenty of room for screw ups that can leave you banging your head against a wall, and the first one to watch out for is loading the truss stacks in the wrong area of the home.
Truss Loading Screw Ups are Just Too Easy to Do
You would be amazed at just how easy it is to do, and how often it happens, but what you’re shooting for is each stack going right where it belongs. Another mistake that can screw you up is spinning them around and landing them on your home “ass backwards”. The no tail end where the tails are supposed to be and the tails where the no tail ends are supposed to be.
Inventory Your Load Then Come Up With a Plan
So the first thing you need to do is break out the truss list, and map that came with your load, and go over the entire truckload of roof trusses stack by stack, to identify and label them. Once you have determined that your entire order is there, and that none are screwed up, then you need to come up with a load plan.
It Sure is Nice When You Can Just Tilt Em Up
What you’re shooting for, is a load sequence that enables you to break into your trusses, and stand them pile by pile, without having to screw around moving or flipping any of them. It’s hard to do, but it can be done, and you must make sure that each stack is laid down in the right direction, so the first trusses that are to be pulled off are on the top of the pile.
Make Sure to Get Everything From the Driver
Your trusses are all in order, and stacked nicely on the top of your frame, so now one would think that all your bases have been covered. Well you are wrong because you have to make sure to get all your metal clips, and all your paper work, including your engineering specs from the truck driver before he leaves.
Tags: Roof Trusses