All gutter guards have the same purpose \u2014 to prevent leaves and other debris from clogging your gutters and at the same time allowing rainwater to flow freely into the waste system or water storage tanks. If they\u2019re not fitted, decomposing leaves, twigs and other items blown in by the wind can cause blockages that result in rainwater overflowing and damaging your property. This accumulated debris can also attract insects and harmful bacteria while birds and other creatures can build nests in unprotected gutters. To overcome these problems, frequent cleaning of the gutters is necessary. However, this can be a messy and dangerous business if you try to do it yourself or can be expensive if you have it done professionally. Whilst gutter guards prevent much of the debris entering your gutters and reduce the needs for cleaning, they\u2019re not all as effective and all have varying costs and different characteristics. The ones you choose may also depend on the location of your property and the local conditions you have to contend with. THE DIFFERENT TYPES OF GUTTER GUARDS AND WHY MESH GUARDS ARE OFTEN THE BEST CHOICE Gutter guards fall into three basic categories, which are: Those that are inserted in the gutters and fill up the space so that debris cannot enter although water can flow freely through them. These comprise either foam filters or brush guards that can be cut to length and simply put in the gutter where they are held in place by friction. These are the cheapest type of guards and also the easiest to install although they are the least resilient, can be displaced by storms and require the most frequent replacement.Debris can become trapped in the bristles and sharp objects such as pine needles can stick in the foam so they do need occasional cleaning to prevent them becoming clogged. These types are also not suitable for bushfire areas as they are not flame resistant.Solid covers that fit over the gutter; these are generally known as reverse curve or surface tension guards. Water flows across the surface and into the gutter via a slot while debris is carried over the cover and past the outer edge of the gutter.This type is generally the most expensive and difficult to fit, requiring professional installation since the cover must closely follow the slope of the roof to work properly. They can be overwhelmed by heavy rain, however, so that water floods over the gutter while small debris can sometimes enter the gutter. They\u2019re also, since they fit on top of the gutter, the most visible.Screen guards come in the form of perforated sheets or mesh that fit across the top of the gutter and allow water to enter but obstruct most debris. Any debris that remains on top of the guard is generally blown away by wind or washed off by rain; if not, it can easily be swept or wiped off occasionally. Mesh is by far the most flexible type of guard, varying from cheap plastic to more durable stainless steel or aluminium and being available in a variety of mesh sizes and shapes. DIFFERENT MESH TYPES AND WHEN TO USE THEM Low quality plastic mesh is very cheap but can be flimsy and may easily break if hit by branches or become brittle if subjected to strong sunlight. Either way, it\u2019s unlikely to last long and will need frequent replacement, which will make it much more expensive in the long term. Stronger poly mesh\u2019s are available which can be great in coastal areas where they would be exposed to salt corrosion. Better options are available and include aluminium, polyethylene and stainless steel that are available in different hole sizes and thicknesses. The one you choose will depend on the location of your premises and the conditions you experience, which include: nearness to the sea, since salt spray in the air can cause corrosion to certain metalsproximity to trees and their type; most guards will deal effectively with large leaves from deciduous trees but pine needles and seeds can penetrate or become stuck in large mesh sizesif in a bushfire area, since some types of mesh are more resistant to fire than otherswhere possums and other vermin are a problem, some mesh not being strong enough to resist them. All these factors and others can influence your choice because you want a type of mesh that will provide effective protection against particular threats and will continue to do so for as long as possible. Polyethylene mesh, for example, can withstand high levels of UV rays without significant deterioration and will last a long time, often more than ten years, but has little fire resistance. Aluminium mesh is also long-lasting, often with a fifteen year warranty, and is very flexible and non-inflammable. Stainless steel is similarly very durable and non-combustible as well as being resistant to corrosion but is a brittle material that may struggle to shape itself to a roof. Most of these materials come in different weights, the heavier versions being strong enough to repel possums and other pests. Some of them are also particularly resistant to ember attack during bush fires. Apart from the material used for gutter guards, the size of the mesh is also a crucial factor. All will let water flow through and larger mesh size will be sufficient to block twigs, leaves, and other large debris. Smaller debris will get through but will often be flushed through the downpipes without causing a blockage. If your property is in an area where pine needles and seeds are blown into the gutter, these can penetrate mesh with relatively large openings. They can eventually cause blockages and the seeds may even sprout in the gutter and cause a real problem. In these situations, a very small mesh size is necessary since this will prevent nearly all debris getting through.