Rot Doctor

[Miscellaneous Q&A Index]

Subject: S-1 coverage

Date: Thursday, June 11, 2020

What is the expected coverage of your S-1 product? If I purchase the gallon size which mixes to 2 gallons how many square feet can I expect to treat? I realize this varies depending on a few variables but I’m just looking for a ballpark figure here. Also, are multiple coats required or recommended?

When used as a primer on good wood, the recommended coverage rate is 300 square feet per gallon (7.3 square meters per liter). Recommended because coverage needs to be regulated, as the wood will accept S-1 at a much greater rate if you apply it, yielding less coverage per unit.

As a primer on good wood, only one coat is necessary, as the wood will be top coated with paint or varnish. If you want to completely seal the wood, and are using S-1 alone, no top coat, then 2–3 coats, letting it dry in between, are required. S-1 alone is not recommended for any application which will get significant UV exposure.

More often, S-1 is used to restore strength to rotted wood. For use on rotted, wood, the answer is, as much as the wood wants to take. Typically, rotted wood will absorb from 20% to 50% of its volume. So, a one gallon chunk of rotted wood will normally absorb 1–2 quarts of S-1 Sealer. It depends on how porous the wood is.

As a treatment for rotted wood, repeated applications, as quickly as the wood will absorb it, until the wood stops or significantly slows absorbing, are recommended. This is one coat. Normally that is all that is required. If the wood is exceptionally porous, applying a second coat the next day, if it will accept more, can be beneficial.


[Miscellaneous Q&A Index]

Have questions?

Contact us by phone 206-364-2155 or e-mail (send us your pictures) at and we will gladly answer questions about our products or how to apply them. With 20+ years of experience and many more in the boating and construction industries, not much surprises us. We are here to help our customers solve their issues. Let us help you to not have any surprises in your repair project.

Our business hours are 6:30 AM to 5:30 PM Pacific Time, Monday–Friday.
Tech support is available over weekends and holidays 8:30 AM to 5:30 PM Pacific Time.

The Rot Doctor, Inc.
P.O. Box 30612, Seattle, WA 98113
Voice: 206.364.2155    Fax: 206.364.4744    E-mail:
The Rot Doctor, Inc. ©1997–2021. All rights reserved.