Trees can often look completely fine on the outside while being hollow with decay on the inside, which seriously compromises the tree’s strength and makes it far more prone to failure.  If left undetected, a hollow tree can pose significant risks, especially if the tree is located near to your home or other structures.

So how can you determine if a tree is hollow without having to cut it down? Here we take a look at what methods can be used and when hollow tree removal is the best option.

Hollow Tree Removal Considerations

1. Visual Assessment

There are often tell-tale signs which can indicate internal decay if you know what to look for. Some of the most common indicators are:

• Cracks, seams or cavities in the trunk
• Fungal growth or mushrooms around the base of the trunk
• Peeling bark
• Significant deadwood
• Sparse foliage

Whilst these signs aren’t necessarily conclusive on their own, they do suggest that your tree could have issues requiring further investigation.

2. Sounding

Arborists commonly use a technique known as ‘sounding’ (also known as the mallet test) to determine if a tree is hollow. This test involves striking the tree, usually with a rubber mallet, and listening to the sound it makes. Generally, a solid, healthy tree will produce a deep, dull thud. While a hollow tree is more likely to emit a higher-pitched, drum or echo-like sound.

The Arborist strikes the trunk in several different places to compare the sounds and identify any variations that could suggest signs of an internal cavity.

3. Using A Resistograph

Your Arborist may use a specialised piece of equipment called a resistograph that drills a small hole into the tree’s trunk and measures the amount of resistance encountered when doing so. If the tree is solid, the resistance level should remain high as the drill passes through the dense wood.

If the resistance level drops suddenly, it can be a sign of decay or a cavity. The resistograph is an excellent tool for determining if a tree is hollow as it causes minimal damage to the tree while providing detailed information about the tree’s internal structure.3. Probing

Often used in conjunction with other methods, probing is a technique that can be used if there are existing cavities or holes in the tree. This technique involves using a long, flexible rod to ‘probe’ a hole. If the rod goes easily into the trunk with little to no resistance this can indicate a hollow cavity within the tree.

4. Probing

Often used in conjunction with other methods, probing is a technique that can be used if there are existing cavities or holes in the tree. This technique involves using a long, flexible rod to ‘probe’ a hole. If the rod goes easily into the trunk with little to no resistance this can indicate a hollow cavity within the tree.

5. Radar And Sonic Tomography

An even more advanced, high-tech method your Arborist may use is ground penetrating radar or sonic tomography. This aims to create a picture of the tree’s internal structure and condition. Sensors are placed around the tree which send sound waves through it. The density of the wood inside the tree is determined by calculating how long it takes for the waves to travel between the sensors. Decayed or hollow areas slow the sound waves down, which produce a map of the tree highlighting areas of concern.

Call The Hollow Tree Removal Professionals

While these methods can provide clues, accurate diagnosis of a hollow tree generally requires professional experience. If you suspect a tree on your property could be hollow, contact your local Arborist. They will carry out an inspection and determine the best course of action to ensure the safety of you and your family. Your Arborist will also be able to determine if your tree can be saved or if it’s best to have it removed.

Hollow Tree Removal In Brisbane

It is not advisable to attempt to remove a hollow tree yourself. Hollow trees can be more dangerous to remove as they are generally more unpredictable in nature. For this reason, removing a hollow tree is almost always best left to the professionals who will expertly and safely remove the tree using the appropriate techniques, tools and equipment.

Call Brisbane’s Aussie Tree Solutions for a free quote on our hollow tree removal and consulting Arborist services. Whatever your tree care and maintenance needs – we’ll get to the root of it! Whether it’s tree removal, stump grinding or consulting Arborist services, we’ve got your covered with over forty years of experience for your total peace of mind.