The Bottom Line About Specifying Abuse or Impact
OnBoard Newsletter | September 2020
Abuse Resistant (AR) and Impact Resistant (IR) gypsum panels are not interchangeable because they do not perform the same jobs. After you’ve finished reading this, we hope you’ll have a better understanding about how and when to specify each.
Abuse Resistant & Impact Resistant Are Not Equal
Abuse Resistant: If what happens to the surface is a major concern, Gold Bond® Hi-Abuse® XP® is an excellent option. It provides more protection than standard gypsum board against surface abrasion – scrapes, scratches and scuffs. For areas where there is not a constant flow of equipment and crowds of people.
Impact Resistant:Gold Bond® Hi-Impact® XP® can take the toughest hits over time, by both people and equipment. It doesn’t need to be everywhere, but where Hi-Impact XP needs to be, there is no substitution.
How They Are Not Equal: Hi-Abuse XP has a lower price point than Hi-Impact XP because it is not designed to endure the same level of force. If you specify Hi-Abuse XP when what you really need is Hi-Impact XP, your client could be subjected to costly repairs over the long run.
See How Abuse Resistant & Impact Resistant Perform Differently
For a product to be classified Abuse Resistant (AR) or Impact Resistant (IR), it must meet the test standards of ASTM C1629. ASTM C1629 has four test methods to quantify a level of abuse/impact resistance. Each test has a classification level (1-3), with 3 being the best.
Hi-Abuse XP and Hi-Impact XP were subjected to the four test methods: Surface abrasion, indentation, soft body impact and hard body impact. The chart below shows their results. As you can see, IR outperforms AR. To watch the tests being performed, click each test method.
- Surface Abrasion, ASTM Test Method D4977
- Indentation Resistance, ASTM Test Method D5420
- Soft Body Impact, ASTM Test Method E695
- Hard Body Impact, ASTM Test Method Annex A1
Stop & Review These Points Before Specifying AR or IR
These tips will help you avoid common mistakes architects and contractors make when determining whether to use Abuse Resistant or Impact Resistant.
1. Consider carefully: This is not a value engineering situation.
Value engineering only works if you’re not sacrificing functionality – but Abuse Resistant and Impact Resistant are not interchangeable gypsum panels. They are two distinct products that perform differently. Where you need IR, there is no substitution.
2. Write “Abuse” and “Impact” in two separate paragraphs in your specification.
Use two separate paragraphs in your specification; one for AR and one for IR. We also recommend listing the four different test methods and preferred classification level for each product type.
3. Call out the specific product on the partition schedule in the drawing set.
It’s important to coordinate the specification and partition schedule. Double check and cross reference everything. Be clear about which wall gets which product. Also identify that on your partition schedules to ensure accurate pricing.
4. Specify the correct stud gauge.
Screw spinout is a complicated issue that occurs in many applications if best practices are not used. Make sure the studs are right for the product you’re specifying. Remember to also include adequate stud thickness on the partition schedule. Specify according to GA-216-2018 section 220.127.116.11. (“Where studs complying with ASTM C645 are used to receive AR or IR gypsum panels, they shall not be less than 0.0312 inch design thickness.” This equals 20 gauge drywall studs, not EQ stud thickness.) Consult GA-216 or talk with your Construction Design Manager if you’re not sure. (Your CDM can also provide a copy of GA-216.)
5. Specify the right product for the application.
Each project has its nuances. To specify the right product (AR or IR), ask many detailed questions, such as how many people will be occupying the space, frequency of use, type of usage. For areas such as university student housing, ask about impact in hallways, common areas and cafeteria multi-purpose rooms. Talk with your Construction Design Manager for more ways to assess whether your project requires AR or IR.
“When it comes to product specific questions, we’re often asked: “Under what conditions do I need to specify abuse- or impact-resistant wallboard?” If the concern is scratch or rubbing resistance, then Hi-Abuse XP will do the job. If you’re worried about more damage than just surface abrasion, then Hi-Impact XP is the better choice. When you think about Hi-Impact XP, think baseball bat stopper! Click on this video and watch our demo.”
Scott HughesConstruction Design ManagerNational Gypsum
Make Your Specifications Clear and Write on Your Drawings
Make sure your written specifications are clear, but don’t stop there. When specific walls need to be Impact Resistant, also write Hi-Impact XP on those walls in your drawing set –– and mark “no substitutions allowed.” Leave nothing to interpretation.
Download ProductMasterSpec 092900 Gypsum Board specification section for your next project.
Your Construction Design Manager is Here to Help
We often get questions about Abuse Resistant and Impact Resistant, so you’re not alone if the waters are a little muddy. Don’t hesitate to call your Construction Design Manager for clarification. He or she can help you make the best choice – AR or IR – for each area in your project and nail down your specification details.
And if your project is subject to extreme moisture or humidity, it may require fiberglass mat AR or IR gypsum panels. Ask your CDM about eXP® Interior Extreme®AR and eXP® Interior Extreme® IR.