Should I Use Treated or Untreated Wood for Indoor Furniture?

A tall stack of 2 X 4 lumber bound with yellow, plastic tape.

If you were to ask 10 people which type of wood they would recommend for an indoor project, half would likely advise using treated wood for durability, and the other half would probably tell you that treated wood is far too dangerous and natural wood is the only way to go.

Take a stroll down the lumber aisle of any home improvement store and you may come away with more questions than answers.

Shouldn’t this be an easy decision? Why all the confusion?

Should I Use Treated or Untreated Wood for Indoor Furniture? When building indoor furniture, untreated wood is a better choice as it contains no chemicals and is just as strong as treated wood. Treated wood is considered safe for indoor use in some circumstances, but there is a risk of chemical exposure. 

As with any project, safety should always be your top concern. Is using untreated wood the best option? Is treated wood really safe? 

Let’s explore the answer to these questions and more to eliminate the confusion that frequently arises when deciding between treated and untreated wood.

Which Wood Is Better for Indoor Furniture – Treated or Untreated?

Generally, untreated wood is a better, safer choice to use for constructing indoor furniture.

Treated wood is technically considered safe to use inside in applications where it won’t often be touched.

This is where the confusion arises. It’s safe to use, but it’s not? Huh?

Why risk exposure to chemicals if you don’t have to?

In most instances, untreated wood will work just as well, is much safer, and will look nicer too.

Let’s look at the pros and cons of both types of lumber so that you can make an informed decision that’s best for your family.

Treated Wood 

When used indoors, there is little possibility of chemicals leaching or releasing toxins into the air because houses are typically dry environments.

You can safely use treated wood for indoor furniture, but only under certain circumstances.

If the item you’re making will be in contact with people, pets, or food, do not use treated wood.

It’s that simple. 

However, if the chance of skin, animal, or food contact is highly unlikely and you’re concerned about potential damage from moisture, treated wood may be used.

For instance, when constructing my kid’s bed frames, I used treated wood for the bottom part of the legs because with kids and pets, we often steam clean the carpets. 

As beds are bulky and heavy, I knew I wouldn’t be moving them around each time I cleaned the rugs, and I didn’t want to take a chance of the legs being stained or damaged by the occasional exposure to moisture. 

Every other piece of lumber used was untreated wood.

The same basic idea can be applied to any indoor furniture project.

Use treated wood where you’d like extra protection and direct contact is unlikely. Use natural wood everywhere else.

Is Treated Wood Dangerous?

According to the Environmental Protection Agency, “Both the treatment process and the use of treated products can result in exposure to pesticides to both people and the environment.”

While many of the older, dangerous preservatives once used, like chromated copper arsenate, have been banned, today’s treated wood is not required to be labeled with a list of chemicals used during treatment. 

Lumber today is most often treated with alkaline copper quaternary (ACQ) and copper azole, though borates, copper naphthenate, copper-HDO, or polymeric betaine may be used as well.

Pros:

  • Great for fences, decks, and other outdoor projects.
  • Resists rot and decay.
  • Protects against insects.
  • Lasts for years.
  • Less expensive than naturally rot-resistant wood.

Cons:

  • Filled with chemicals.
  • More difficult to work with.
  • Heavier than untreated lumber.
  • Protective gear such as masks, long sleeves, and gloves should be used.
  • Takes a long time to dry out.
  • The wood’s natural beauty is diminished.
  • More expensive than untreated softwood lumber.

When to Not Use Treated Wood

Pressure-treated wood certainly is useful in the proper applications, but there are some instances where you definitely do not want to use it.

Around Babies and Children

Little ones explore the world with their hands and, all too frequently, their mouths. 

If you have children, hope to have children one day, or frequently have pint-sized guests in your home, steer clear of treated wood and opt for wood in its natural form instead.

Around Pets

Most puppies and some dogs have a tendency to gnaw on wooden items such as table legs.

Cats often enjoy sharpening their claws on furniture, much to the owner’s dismay. Not only can this leave deep scratches in the wood, but toxins may cling to the claws.

Guess what the cat will wind up ingesting the next time he licks his paws while grooming. Not good.

If you’re planning on constructing any type of animal enclosure, such as a rabbit hutch or a maze for your pet rat, it’s best to stick with wood in its natural form. 

If you go with the treated version, plan accordingly and use wire screening to ensure that the critter will never have direct contact with the wood. 

On Surfaces that May Come in Contact With Food

You and your family do not want to risk ingesting the chemicals in treated wood.

Butcher blocks, counter tops, cutting boards, and table tops should never be made with pressure-treated wood.

If You Plan to Paint or Stain Right Away

Because treated wood has been saturated with chemicals, it’s usually still pretty damp at the time of purchase. 

It can take a long time for it to dry out and shrink back to its original size, sometimes as long as several weeks. While it is still wet, any attempts at painting or staining will be disappointing. 

You’ll likely deal with streaking, cracking, peeling, and color bleeding, and the project that you worked so hard on will be an unsightly mess.

Will Painting or Varnishing Seal in Chemicals?

Maybe. There really haven’t been sufficient studies to prove that paint, stain, or varnish will make treated wood totally safe.

Logically, you might think that sealing in chemicals negates any potential danger, but we just don’t know for sure at this point. 

You also need to consider the inevitability of the paint or varnish wearing away over time, and nicks, scratches, or dents removing the wood’s finish in some places entirely. 

One little bump with a hard object and you’d be once again left with exposed treated wood.

Is it worth taking the chance? I don’t think so.

Untreated Wood 

Untreated lumber is, for the most part, unadulterated wood in its natural form. The only modification it undergoes is the milling process where it is cut into boards. 

No dangerous chemicals are added, so untreated wood may be used safely for a wide variety of indoor furniture projects, even those that will come into contact with food on a regular basis, like a butcher block or table top.

Many people assume that because pressure-treated wood is heavier than natural wood, it must be stronger. This is false.

Untreated wood will support just as much weight as treated wood will and is just as strong.

Because untreated wood isn’t swollen and wet from chemical treatments, it is much easier to work with. 

There is less resistance when cutting, even if you’re only using hand tools.

Driving or removing nails and pre-drilling holes for screws is also much easier, again because there is less resistance.

Untreated wood, unless it was stored unprotected outside, will be nice and dry and ready to paint or stain whenever you are.

Pros:

  • Safe to use for human and food contact.
  • Natural – no chemicals.
  • Just as strong as treated lumber.
  • Much easier to cut, drive nails into, drill, etc.
  • Weighs less than treated wood.
  • Will accept paint and stain readily.
  • Less expensive.
  • No masks, gloves, or protective gear necessary.
  • More aesthetically pleasing.

Cons:

  • Subject to damage from insects, moisture, age, etc.
  • May warp if wet.

The Bottom Line

Why take unnecessary risks?

Whenever possible, use untreated wood when building furniture for indoor use. Save the treated lumber for outdoor construction work.