The Engineering Letter: What It Is and Why Contractors Use It

Every Florida contractor has hit that moment where the work is done, but the job can’t move forward. Maybe the inspector didn’t show. Maybe a surprise issue needs verification. Maybe you’re trying to close out a permit, but the city’s behind, the scope changed, or you need something in writing that goes beyond your crew’s photos.

That’s where an engineering letter comes in.

Sealed engineering letters have become one of the most useful tools for contractors navigating storm season delays, city inspection backlogs, and shifting scopes of work. But they’re not all created equal, and using them the wrong way can do more harm than good.

Here’s what you need to know about engineering letters: what they are, when they help, and how to get the most out of them.

What Is an Engineering Letter?

An engineering letter (or sealed letter) is a written document prepared and signed by a licensed engineer. It includes professional observations, technical findings, or a confirmation of site conditions. These letters are often required by building departments, lenders, insurance carriers, or owners to confirm that work was completed properly or that certain conditions were met.

When Contractors Use Them

• To confirm installation meets code when the inspector can’t come
• To document structural tie-ins, fastener layouts, or waterproofing before concealment
• To certify conditions before or after a change order
• To help support a draw request or invoice
• To document weather-related delays or risks on site
• To close out a permit when the work is complete, but inspections are stalled

Why They Matter During Storm Season

When the weather is working against you or the city can’t keep up, sealed engineering letters help keep your momentum. For example:

A roofer installs underlayment just before a storm. The city inspector is booked out for days. The contractor calls PES, we document the work, and issue a letter confirming the correct materials and methods were used. The crew proceeds with the rest of the job.

A window installer completes a multi-unit project, but a few units get held up. Rather than delay the payment or fail the inspection, an engineer inspects and issues a partial approval letter so the rest of the work can be certified.

How to Request the Right Letter

Not all engineering letters are the same. Be clear about:

• What the letter needs to verify
• Who the letter is for (city, owner, insurance, lender, etc.)
• What format or language is required (some cities provide templates)
• The urgency and timeline for delivery

If you’re unsure, just ask. At PES, we help contractors understand what’s required and make sure the letter holds weight.

Think of an engineering letter as your job site’s backup generator. When the system breaks down, due to weather, city issues, or scheduling conflicts, we help keep things running. But don’t wait until you’re stuck. The earlier we’re looped in, the better we can protect your progress.