Can You Apply a Floor Stain Over Existing Floor Stain?
Can Stain Be Applied Over Existing Stain? The short answer is; It’s possible, but only under certain conditions. However, the answer that you get will entirely depend on who you ask. This is a controversial topic even among professionals who have been in the industry for 30 years or more. Some hardwood floor refinishing professionals will stain over existing stains while others will not. But what we’re going to do in this article is look at the science behind the opinions. Although we’re not chemists or scientists, we can at least apply basic logic to this ongoing debate.
There are cases where a customer’s wood floors are in pretty bad shape, where the finish is all but gone, and a significant portion of the existing stain may be missing while other parts of the floors still have the original stain. Some professionals will provide a screening of the floor and instead of just color matching and correcting the missing stain areas, they will apply the water-based stain over the whole floor, both over the old stain and bare wood. After applying 2 coats of finish the appearance of the floors can be drastically improved. The final results can appear absolutely stunning compared to their original state.
But we have to ask a few questions;
- Is that technically the best way to treat hardwood floors under those conditions?
- Is there a higher risk of premature finish failure in the near future?
Hardwood Floor Best Staining Practices
First and foremost, it has long been said that the best method for staining floors is always going to be sanding them down to bare wood and applying a new stain. This allows the stain to be fully absorbed into the fiber and grain of the wood. Keystone Hardwood Floor Care uses either Duraseal Quick Coat Stain or Bona DriFast Stain. Both of these products are oil-modified stains with a built-in sealer that will accept a water-borne polyurethane finish over them. Drying and cure times vary depending on stain colors. Applying finish over the above-mentioned stains is also optional, as they are also stand-alone finished sealers. That being said, there are times when the customer may not have the budget for sanding down to bare wood and just want to get the floors protected from further damage and looking better than their current state. At this point, there are a few limited options for the homeowner.
When Staining Over the Top of Stain May Work
Water-Based Stains and Oil-Based Modified Stains
Water-based stains are fairly thin and can be absorbed into most porous hardwoods. Oil-based modified stains are thicker but as long as the hardwood is porous, it will be absorbed as well. If you are considering staining over hardwood floors where the old stain is still present in areas, there is a simple test you can do to see if it’s going to absorb. Get a stain color that closely matches the existing stain. After screening the wood floors and cleaning the floors, test a few areas by applying a little stain. Take an eye dropper with color-matched stain and put a drop of it over an area of bare wood and an area with the old stain is still present. For either area, the stain should start to absorb into the wood. If either area doesn’t at least partially absorb, then chances are the new stain won’t take. You’ll need to use a more abrasive treatment for the hardwood prior to staining. After just a few minutes, wipe off any excess and observe for color penetration. If both the bare wood and existing stain areas have some color penetration and absorption, then it may be okay to proceed to stain the whole floor. Just be sure to wipe off all excess and do not allow puddling anywhere. The objective is to wipe off all excess stain that hasn’t been absorbed.
Disclaimer: We say “may be okay to proceed to stain the whole floor” because there are no 100% guarantees that premature finish failure can be avoided when applying stain over old stain. The problem is that when the stain isn’t absorbed into the wood, then you’re essentially overlapping a new stain over an old stain, and can create unbonded layers. However, if the stain has absorbed into the wood floor, both bare and old stain areas, then chances are you be okay with proceeding. Just keep in mind, that the above method of applying stain has too many unknown variables and unless assessed by a professional, we do not recommend it.
When Staining over Old Stain Is Not a Good Idea
There are circumstances where it is not a good idea to apply a new stain over the whole floor where the existing stain is present. These circumstances include:
- There is existing finish left on the floors
- The floors are contaminated with floor cleaning and polishing products (wax, oils, acrylics)
- The hardwood floors are not porous
- Aluminum oxide prefinished floors
- Engineered floors that are prefinished
- All hardwood floors that aren’t properly prepped for receiving stain
It is critical that the hardwood floors are properly prepped for receiving stain by whatever means is necessary for the circumstance. There is a higher risk of stain and finish failure when these criteriums aren’t met. You may not see the failure in 2 days, 2 months or 6 months, but eventually, there will be a premature finish failure. The failure may be polyurethane flaking, peeling, or bubbling.
As hardwood floor care professionals, we want to provide a solution for our customers that best fits their budget. When a full sanding is not an option, we may be able to customize a plan for your particular project. We’ll be honest with you up front. If your floors are too far damaged, and restoring them will nearly cost the same as new floors, we’ll explain that during our assessment. Some of our customers know that sanding is the best option for their floors but may not be in a position to have that done, so we try to provide the next best option. This is especially true for hardwood floors that have no finish left to protect them. At a minimum, we need to get a protective layer over the floors to prevent further damage.