Last Updated on July 4, 2026 by Sam Wood Worker
Quick Answer: Cumaru wood is one of the best choices for decking and flooring because it is very hard, resists water, and does not rot easily. For decking, it can last 25 years or more outside. For flooring, it gives a warm, rich look and holds up well against daily foot traffic. The main things to plan for are the higher cost, the extra work needed to cut and drill it, and proper spacing so the boards do not push against each other when they expand.
If you are trying to decide between cumaru for your deck or your floor, I want to help you the simple way, like a friend explaining it over coffee, not like a textbook.
Why I Started Using Cumaru For Decks
The first deck I built with cumaru was for a customer who wanted something that would not need replacing every ten years. I remember laying the boards down and thinking, this wood is heavy, almost like carrying a small log every time I picked one up. But once it was installed and sealed, it looked amazing. Three summers later, I visited that same deck. No cracks, no soft spots, no sign of rot. That is the moment I understood why people are willing to pay more for cumaru.
Cumaru wood For Decking: What You Need To Know
Cumaru decking is popular because it handles rain, sun, and moisture without warping easily. It is naturally resistant to bugs too, which matters a lot if your deck sits close to the ground. If you are worried about bugs eating into your wood over time, our guide on wood-destroying pests explains what to watch for, though cumaru handles this much better than softer woods.
Practical Scenario: Building A Backyard Deck
Say you are building a 12×16 foot deck. Before you even touch cumaru boards, you need the right blades and drill bits, since normal ones wear out fast. I always tell people to check their deck building tools first, because using the wrong tool on cumaru is like trying to cut steel with a butter knife.
You also want to know exactly how much lumber to order. Nobody wants to run short halfway through a project. Our dimensional lumber sizes guide helps you plan the right board sizes before you buy.
Spacing And Fastening Tips
Cumaru expands and shrinks a little with weather changes, just less than softer woods. Leave a small gap, around 3/16 inch, between boards so they have room to move. Always pre-drill your holes. I learned this after cracking two boards on my first job because I skipped this step, thinking the wood would be forgiving. It was not.
Cumaru For Flooring: A Different Kind Of Beauty
Flooring is where cumaru really shows off its color. Indoors, away from direct sun and rain, the reddish-brown tone stays rich for years. It also handles daily foot traffic well because of how hard it is.
If you compare it to something like prefinished hardwood floors, cumaru holds up noticeably better against dents from furniture legs or dropped items. I once put in a small cumaru floor section in a home office, and two years later, even with a rolling office chair going back and forth daily, there were barely any marks.
Practical Scenario: Choosing Between Cumaru And Oak Flooring
If someone asks me whether to pick cumaru or oak for their living room, I ask them one simple question: do you want a classic warm look, or something bold and reddish-brown? If they want classic, I point them toward solid oak flooring. If they want something that looks a little more special and lasts just as long or longer, cumaru wins.
Another option some people like is herringbone flooring patterns using cumaru boards. It looks stunning, but it does take longer to install because of the cutting pattern, so plan extra time.
Cumaru Decking vs Flooring: Side-By-Side
| Factor | Decking | Flooring |
|---|---|---|
| Exposure | Outdoor, weather, sun, rain | Indoor, controlled environment |
| Maintenance | Oil every 1-2 years | Occasional cleaning, less oiling |
| Lifespan | 25+ years | 30+ years indoors |
| Look | Ages to silver-gray if untreated | Stays rich brown longer |
| Installation Difficulty | Moderate, needs spacing and pre-drilling | Moderate, needs acclimation time |
Cumaru vs Ipe For Your Project
Both woods look similar and perform similarly, but cumaru usually costs less. If your budget is tight but you still want that premium hardwood feel, cumaru gives you almost the same durability as Ipe wood without paying the full Ipe price.
Cost And Budgeting
Cumaru is not the cheapest wood, but it is usually more affordable than Ipe. Many homeowners underestimate the total cost of a deck or flooring project. If money is tight upfront, you might want to look into financing options for large woodworking projects or specifically how to finance a deck, since spreading out payments can make a cumaru deck much more realistic for a normal budget.
How To Keep Cumaru Looking Its Best
- Check moisture before installing. Wood that is too wet when installed can shrink later and cause gaps. A good moisture meter takes the guesswork out of this step.
- Oil your deck regularly. For outdoor cumaru, oiling once or twice a year keeps the warm color instead of letting it fade to gray. Use a proper oil-based stain made for dense hardwoods.
- Pick the right outdoor stain. Not every stain works well on oily hardwoods like cumaru. Our best wood stains for outside guide has options that actually stick and last.
- Let indoor flooring acclimate. Before installing cumaru flooring, let the boards sit in the room for a few days so they adjust to the humidity level.
- Sand gently if needed. Cumaru is so hard that you rarely need heavy sanding, just light touch-ups over time.
Key Takeaways
- Cumaru works great for both decking and flooring, but each has different care needs.
- Outdoor cumaru decking needs oiling, spacing, and pre-drilling.
- Indoor cumaru flooring holds its rich color longer since it avoids direct sun and rain.
- It costs more than basic woods but less than Ipe, while offering similar strength.
- Proper tools and moisture checks prevent most common installation mistakes.
Frequently Asked Questions
Is cumaru good for outdoor decking? Yes, it is one of the best choices for outdoor decking because it resists rot, decay, and most pests naturally.
Can cumaru be used for indoor flooring? Yes, cumaru flooring is durable and keeps a rich color indoors, especially away from direct sunlight.
How much space should I leave between cumaru deck boards? Around 3/16 inch is a safe gap to allow for natural wood movement.
Does cumaru flooring need to be sealed? It is not required, but sealing helps maintain the color and adds extra protection against scratches.
Is cumaru more affordable than Ipe? Yes, cumaru usually costs less than Ipe while offering similar hardness and durability.
My Final Thoughts
Whether you are building a deck that needs to survive years of weather, or putting in a floor that needs to survive years of foot traffic, cumaru handles both jobs well. It takes a little more effort during installation, but every customer I have worked with who chose cumaru has thanked me years later when their deck or floor still looks brand new. If you want to understand the wood itself a little deeper before starting your project, my full breakdown on cumaru wood uses, drawbacks, and comparisons is a good place to start.
