Quick answer: A DIY cat tree needs 18 mm plywood for the base and platforms, solid timber posts, natural sisal rope, wool or canvas pads, wood glue, screws or bolts, a pet-safe finish and a wall anchor. The frame lasts many years, while sisal and pads are cheap consumables, which is why a solid DIY tree often has a low cost per year.
When people compare DIY and store-bought cat trees, they usually compare the total price on day one. A more useful view splits a tree into its parts: the frame, which should last for many years, and the consumables, which wear out and get replaced. Seeing the materials this way makes the cost per year comparison much clearer.
This guide is a shopping list with lifespans. For the formula and the stability side, see cost per year of use and the stability test.
The full materials list
| Part | Material | Role | Expected life |
|---|---|---|---|
| Base | 18 mm plywood | Stability | Life of the tree |
| Platforms | 18 mm or 15 mm plywood | Resting, jumping | Life of the tree |
| Posts | Solid timber, 70 to 90 mm | Structure, scratching core | Life of the tree |
| Scratching surface | Natural sisal rope 8 to 10 mm | Scratching | Months to a couple of years |
| Pads | Wool felt or canvas covers | Comfort, grip | One to several years |
| Joinery | Wood glue, screws, bolts, dowels | Strength | Life of the tree, tighten yearly |
| Finish | Water-based or hardwax | Protection | Refresh every year or two |
| Anchor | L-bracket or anti-tip strap | Safety | Life of the tree |
Frame versus consumables
Every cat tree has two kinds of parts. The frame, meaning the base, posts, platforms and joints, carries the load and decides whether the tree is stable. The consumables, meaning sisal, pads and finish, take the daily wear from claws and bodies. In a well-built tree, the frame outlives several sets of consumables. In a poorly built tree, the frame fails first, and the whole thing goes to the tip with plenty of usable rope still on it.
Spending more on the frame and less on decoration is the simplest way to lower cost per year. Our materials and longevity guide explains how different woods and fibres age.
Plywood: the backbone
Plywood is the best value material for bases and platforms. It is strong, stable and holds screws well. Use 18 mm for the base, because weight low down improves stability. Platforms can be 15 or 18 mm depending on size. Birch plywood is strong and smooth; veneer plywood in oak or walnut looks like furniture. Ask the timber merchant to cut panels to size, which saves buying a saw. Our plywood versus solid wood guide compares the options.
Posts: solid, not hollow
Use solid timber posts rather than cardboard tubes. Pine or spruce is affordable and fine once wrapped; hardwood such as oak or ash is stronger and looks good left partly bare. A post of 70 to 90 mm square suits most cats. Solid posts hold bolts, can be rewrapped many times and do not crush. They are the main reason a DIY tree outlasts trees built on tubes.
Sisal: the main consumable
Natural sisal rope is the part you will replace. Buy untreated rope in 8 to 10 mm thickness and estimate around 25 to 30 metres per metre of post, depending on diameter. Buy extra so you can rewrap without matching a new batch. Glue every few turns so a cut strand does not unravel the whole wrap. Our sisal fabric versus rope guide explains which lasts longer in heavy use.
Rewrapping a post takes an hour or two and costs a fraction of a new tree, which is the heart of the cost per year advantage.
Pads and textiles
Platform pads make a tree comfortable and stop cats slipping. Wool felt is durable and natural; canvas covers with foam inside are washable. Avoid carpet glued to plywood, which traps hair, smells over time and cannot be replaced without stripping the platform. Removable pads cost little to replace and keep the tree looking new.
Hardware and joinery
- Wood glue for all permanent joints
- Wood screws 50 to 80 mm for platforms into posts
- Coach bolts or threaded inserts for posts into the base
- Dowels for hidden joints where needed
- Corner brackets for extra strength under platforms
- Felt pads for the base on hard floors
Hardware is a small part of the budget but a large part of the stability. Do not skimp on screw length or base bolts.
Finish and safety
A water-based clear finish or hardwax oil protects plywood and timber from moisture and dirt. Choose a product that is safe once cured and allow the full cure time before cats use the tree. Avoid essential oils and strongly scented products. Ventilate while finishing; EPA guidance on indoor air quality explains why airflow matters.
The wall anchor
An L-bracket or anti-tip strap fixed into a wall stud is a small purchase that adds a great deal of safety for trees taller than about 120 cm. The CPSC Anchor It campaign explains why anchoring tall furniture matters.
Tools you might need
A drill and driver, a sander or sanding block, a tape measure, a square, clamps and a utility knife are enough if panels are cut for you. A circular saw or jigsaw helps if you cut your own. If you have to buy tools just for this project, include them in the cost, or borrow them. Many tools will be used again, so it is fair to spread their cost.
Cost per year by part
Think of the frame as a one-time cost spread over many years, and the sisal and pads as small annual costs. A store-bought tree bundles all of these together, and if its frame fails, you replace everything, including parts that still had life. That is the key difference: a DIY tree lets you replace only what wears out. Our long-lasting scratcher build shows the same idea applied to a scratching post.
A sample bill of materials for a 150 cm tree
For a two-post tree around 150 cm tall with three platforms, a typical list is one base panel of about 60 by 60 cm in 18 mm plywood, three platforms of about 40 by 50 cm, two solid posts at roughly 70 cm and 110 cm, around 50 metres of sisal rope, three pads, a small box of 60 mm screws, four coach bolts, a bottle of wood glue, a tin of finish and one wall bracket. Exact sizes depend on your room and cat, but this gives a realistic shopping list.
Lay everything out before you start. Missing a single bolt halfway through is the most common reason builds stall.
Materials to avoid
Avoid treated or oiled rope, which can smell and may contain chemicals you do not want on a cat's paws. Avoid glues with strong solvents. Avoid thin hardboard for platforms, which sags. Avoid long dangling toys on elastic, which can tangle. These small choices make the tree safer and help it last.
Budget builds that still last
If budget is tight, keep the frame quality and simplify the design. One solid post and two platforms on a wide plywood base will outlast a large tree made from thin board. Cardboard can work for horizontal scratchers and low pieces, as our budget cat tree under 40 guide shows, but tall structures need plywood and timber. When you have more budget later, add a second post or platform to the same base. A stud-safe build can grow over time.
Shopping tips
Buy plywood and timber from a timber merchant rather than a big box store if you can; quality and cutting are often better. Buy sisal in bulk from a supplier that states it is untreated. Collect offcuts for future small projects such as a wall scratcher. Check the AAFP/ISFM Environmental Needs Guidelines for what cats need from vertical spaces, so your materials serve the right design.
FAQ: DIY Cat Tree Materials and Cost Per Year
What is the most important material in a cat tree?
The base and posts, because they decide stability and lifespan.
How much sisal do I need?
Roughly 25 to 30 metres per metre of post for 8 to 10 mm rope, depending on post size.
Can I use MDF or particleboard?
They are cheaper but hold screws poorly and do not last as long as plywood.
Which parts will I have to replace?
Mainly sisal and pads. The frame should last many years.
Is carpet a good covering?
It traps hair and is hard to replace, so wool or canvas pads are better.
Do I need hardwood for the posts?
No. Pine or spruce posts are strong enough once wrapped in sisal. Hardwood mainly matters if you want bare wood sections to look good and resist dents.
