Find answers to some of the most common questions asked about our doors and entryway systems, staining, painting and other finishing, and our warranty.

General FAQs

What are the advantages of fiberglass over wood and steel?

Unlike wood doors, fiberglass won't dent, crack, split or splinter. Unlike steel doors, fiberglass won't dent, rust or warp. Fiberglass also resists shrinking and swelling with temperature changes, allowing the finish to last three times longer than on a wood door. And the solid polyurethane foam core offers five times greater insulation value than wood doors.

Why should I select a Therma-Tru Benchmark door?

Therma-Tru is the market leader and innovator in fiberglass door technology. Our fiberglass doors are more durable and energy-efficient than wood or steel doors, and are backed by the best full-system warranties in the industry.

How can I get pricing for Therma-Tru Benchmark doors?

Visit Lowe's and see a sales associate in the millwork department to customize your door.

Where can I get replacement parts for my Therma-Tru Benchmark door system?

Visit our Replacement Parts page to determine which parts are available online or exclusively at Lowe’s.  You can also visit your local Lowe’s and see a sales associate for replacement parts.

Can I take a glass style from the Therma-Tru family and use it in a Therma-Tru Benchmark door?

No. The glass styles are unique to each brand and cannot be interchanged.

What are the rough opening dimensions for the Therma-Tru Benchmark door systems?

Find out in this dimensions data pdf.

How do I install a Therma-Tru Benchmark door system?

Download our Installation instructions PDF.

What is the warranty on the Multi-point Locking System?

Our multi-point locking systems are all covered by our standard limited lifetime warranty.

What finish options are available for the Multi-point Locking System?

They are available in Polished Brass, Brushed Chrome and Matte Black.

Finishing FAQs

Is the outdoor temperature extremely important while finishing?

Yes, the outdoor temperature is extremely important. The temperature should be between 50 and 90 degrees Fahrenheit and humidity under 95%.

What if the weather is not accommodating to finish the unit? How do I protect the jambs and door?

If you prime or clear topcoat all unfinished wood components, you can wait about two weeks until the weather is more accommodating.

Can I use lacquer thinner?


Do I sand the door before staining or before applying a second coat of topcoat?

No, this is not recommended or necessary to sand for the topcoat to adhere.

Do "quick dry" paints work on fiberglass doors?

No. Quick dry paints often have fast evaporating solvents like acetone and some slower evaporating solvents.  The typical result is blistered paint.

What is the 'white powder' that has appeared on my door stained with the Therma-Tru finishing kit?

We see this when Therma-Tru stains have been applied very heavily.  There are UV inhibitors in the stain, which will migrate through the topcoat when there is a lot of stain on the door. Wash it off with detergent and water. It may come back one or two more times, but will eventually cease. To prevent this effect in the future, use less stain. Most doors do not require heavy stain coats to achieve dark colors.

What paints can be used on Benchmark by Therma-Tru smooth surface without priming?

Benchmark by Therma-Tru smooth collection doors come ready to paint.  After cleaning, paint the door using a high quality exterior grade acrylic latex paint.  Be watchful of paints with major ingredients like "vinyl polymers" or "polyvinyl acetate" or that are labeled "interior/exterior" in many cases they do not adhere well to Smooth-Star. 

Can I use Super-Paint by Sherwin-Williams' on Benchmark by Therma-Tru Smooth surface doors?

Super-Paint should be used cautiously.  Our laboratory results show that the application is sensitive to environment conditions such as temperature, humidity, etc., during the painting process.

Can I order prefinished doors?

Yes, visit Lowe's and see a sales associate in the millwork department to customize your door.

How do I obtain stain?

Call 1-877-99-STAIN

Do I have to take the door off its hinges before finishing?

No. The weatherstripping can be pulled out of the jambs, so it can be closed and locked during the drying period. Weatherstripping can be pushed back into the jambs after topcoat has dried.

How much area will one kit cover?

Our stain kit includes everything you need to finish the inside and outside of a complete double door unit, an 8’ door unit, or a single door with two sidelites.  It contains stain, topcoat, several brushes, rags, gloves, mineral spirits, stir sticks and two skin samples.

What do I use to clean the door with?

Using a clean, dry rag, clean the entire surface of the door with a mild soap and water.  Rinse soap off thoroughly and allow to dry completely.

Which Benchmark by Therma-Tru doors can be stained?

Wood Grained Doors.

What stain should be used on Therma-Tru Classic-Craft or Fiber-Classic fiberglass doors?

We recommend the Therma-Tru stain kit.  However if you wish to use a different kit, we recommend an oil based stain with a water based top coat.  Be sure to finish all exposed sides, edges and ends of the door.

What paint should I use on the Benchmark by Therma-Tru wood grain?

These doors should be primed and painted with a high quality acrylic, alkyd or oil-based exterior house paint. Primer and paint should be produced by the same manufacturer and be made to work together. Paint all exposed sides, edges and ends of the door.

Do I have to prime wood grained doors?

No. Priming is not necessary or recommended unless you are painting your door. For best adhesion, we recommend priming the door with an alkyd-based or acrylic-based primer before painting.

Can you stain wood components on doors?

Yes. Door edges, wood frames, doorlite frames, brickmould, decorative panels, jambs and mullions are all door components that can be stained.

My wood jambs are clear and I want to stain them. Do I do anything different?

You could purchase a can of wood sealer or wood conditioner and apply it to the jambs to limit the penetration of the stain. The stain is a heavily pigmented stain and could stain the jambs darker if you do not apply a sealer or conditioner first.

What if I don't like how the stain looks and I just finished it? What can I do?

 If you just want to lighten the stain a little, then use your brush with mineral spirits on the tips and lightly brush the stain and wipe the excess onto a clean rag.

Can I apply a second coat of stain to make it look darker?

Yes.  We recommend applying the stain in thin, successive coats to achieve the desired color.

Should I apply a coat of wax over the topcoat?

No, because it already contains some wax and silicone in the formulation. Water will bead up on it and run off.

How do I maintain the topcoat?

When you notice the topcoat beginning to fade, lose its gloss, or feel rough to the touch, then clean the door with mild soap and water, rinse and let it dry completely. Reapply one very thin coat of the topcoat to all surfaces of the door.

Do I have to prime my Benchmark by Therma-Tru smooth surface door?

No, it is not necessary to prime the door, but if your door has a doorlite in it, then the molding around the glass should be primed with an acrylic primer. Wipe the frame with a clean cloth first, then prime and paint.

How do I repair nicks and scratches or scuffs in the stained finish on my door?

Clean the area first with mineral spirits or an all-purpose cleaner. Then, use a small artist brush or cotton swab to apply stain to the nicks or scratches. Carefully wipe or brush off excess stain, let dry and apply a thin coat of the topcoat over the repaired area. Also, there are a variety of “touch-up markers” or repair pencils that repair scratches or nicks in finishes on fine wood furniture.

How do I strip a fiberglass door to restain/repaint it?

To strip our fiberglass doors of paints, stains or topcoats, use a methylene chloride-based stripper. We recommend Savogran® SuperStrip®, Savogran® Kutzit®, or Dad’s Easy Spray® Paint, Stain & Varnish Remover.  Do not leave stripper on the door any longer than 2-3 minutes. You may use a nylon bristle brush to remove any stubborn residue. Wipe the door clean then thoroughly wash the door with a mild soap and water.  Make sure the door is completely dry before refinishing.

The stripper says to not use it on fiberglass. Can I use it?

Fiberglass doors manufactured by Therma-Tru are made from a fiberglass material that you can safely use the recommended strippers on. Follow our finishing instructions for stripping.

Does the staining kit contain strippers?

No. Stripping materials have to be purchased separately.

How do I remove any excess glazing from around the lite frame?

Please see for a video on step by step instructions.

Warranty FAQs

What are the warranties on Therma-Tru Benchmark doors?

You can find a printable of our warranty here.