Some will look at a few to be sure they are installed correctly, some will say, ye those are trusses and walk away after looking at the stamped calcs. Inspector and location dependent, if your are in a builders development, do not expect much more than a cursory look.

They look at the wood quality, the joinery of the manufacturer, the joining olates being fully seated, spacing per plans, attachment to the plates and hurricane ties, and anything else they want to look at. Includung the engineering calculations.

The truss layout shows trusses to be 24" apart. We are planning to add some 2X4 skylights in this 24" space between two trusses. Does that need trusses to be redesigned by the truss designer ?

Also while installing trusses if we reduced gap between two trusses to 16" and add some extra trusses compared to layout is that okay ?

I want to align the skylights with the island in the kitchen and need a specific spacing between two skylights. Hence above questions.

What they inspect is often based upon the relationship between the inspector and the contractor. Some get approval without the inspector getting out of his truck.

Since they don't climb ladders, inspection will be from the floor, mostly looking at lateral bracing and an overview that the bulk of it matches the truss drawings.

If you are making changes to the roof diaphragm then the truss drawings have to show that.

Maybe slow down and don't get married to your idea about some skylights - think an idea through fully. How will you then (artificially) light the island. Will you have deep skylight wells and how is that aesthetic. Will you have direct sun coming in creating a blinding and temperature hot spot on your counter. Etc.

If you want skylights bigger than your truss spacing, or interfering with your truss spacing, then you need an architect to design a different roof plan, with differently specified trusses. That is not ”just” the truss manufacturer that needs to change things. It is a big deal. A big deal.

Nominal 24" wide skylights are usually designed to fit between rafters or trusses so they usually have a 21" to 21 1/2" rough opening width so it shoudn't be necessary to redesign the trusses but the skylights should have been shown on the submitted framing drawings. I suspect the worst case is you'll have to submit as-built drawings stamped by an engineer. To be safe, get the drawings done now.

If the 24” skylight aligns with the truss spacing shown on the engineering, there should be no issues with inspections, as long as the original structural plans on site align with what was built.

If you have taken the liberty of adjusting spacing of the trusses to fit your desired location of the skylight, then you have compromised the structural ability of the roofing support. That requires reengineering the roof, and replacing or altering some trusses. The only ones who can specify if altering a truss is possible, are the exact engineers who designed it from the beginning.

It is a can of worms to open. But it is better than your roof sagging and collapsing because of an unapproved change. Or failing an inspection. Which you have already done. That raised red flags with the inspection department to scrutinize your project even more closely on all future inspections. Better familiarize yourself with the IRC.

> When the city inspectors inspect truss roof, what all they check and review.

Typically:

1. Check that trusses installed at the design spacing.

2. Trusses have a manufacture stamp and approval.

3. Trusses were not field modified.

4. Trusses properly fastened to avoid uplift.

If the skylights are sized properly you shouldn’t have to worry about the building inspector.
What is specified for the skylights?
What was shown on the permit drawings?

@RES2 our permit drawing showed a 4X4 skylight and a truss plan to support that 4X4. However while installing trusses we decided that instead of one 4X4 we can place two 2X4 and for this the contractor placed the trusses slightly different from how it’s showin plan. However still the maximum gap between any two trusses is 24, but some trusses have less than 16” gap. Also in the original plan the two trusses supporting the 4X4 skylight on each side we 2 trusses stick together. But the contractor installed only one. I am checking with contractor if he got an OK from truss company when he did this change or he did it himself.

We haven’t gone through inspection yet. I want to make sure we have necessary documentation submitted for the change we did compared to approved plans and then schedule the inspection

The truss roof should cover most all the inspections.

(it is a holiday weekend and I had to say it)

(Happy Independence Day!!)