What is the required edge overlap for poly underlayment under a concrete slab?

Unlock all questions

This demo includes only 20 questions. Upgrade to access hundreds of questions, flashcards, exam simulations, and disable ads.

Full question bankExam simulationsFlashcards
From $9.99Unlock all

Study for the B3/61 Contractor Trade Exam. Use our comprehensive quizzes with flashcards and multiple-choice questions, each complete with hints and explanations. Be confident and well-prepared for your exam day!

Multiple Choice

What is the required edge overlap for poly underlayment under a concrete slab?

Explanation:
When laying poly underlayment as a vapor barrier beneath a concrete slab, seams must be overlapped by six inches and sealed. This sufficient overlap ensures the barrier remains continuous and minimizes moisture transmission through joints. Butt edges would still leave gaps in the barrier, and overlaps of only half the sheet or just a couple of inches aren’t reliable for preventing moisture movement. Six inches is the standard requirement to maintain effective vapor protection under the slab.

When laying poly underlayment as a vapor barrier beneath a concrete slab, seams must be overlapped by six inches and sealed. This sufficient overlap ensures the barrier remains continuous and minimizes moisture transmission through joints. Butt edges would still leave gaps in the barrier, and overlaps of only half the sheet or just a couple of inches aren’t reliable for preventing moisture movement. Six inches is the standard requirement to maintain effective vapor protection under the slab.

More Multiple Choice Questions
Subscribe

Get the latest from Examzify

You can unsubscribe at any time. Read our privacy policy