Fatigue. Fiberglass boats endure several sources of stress and the hull will lose its strength due to the impact of waves and vibration. Waves cause the greatest damage and can significantly reduce the boat's service life. Vibration mostly results from the weight of the boat dragging on the water.
Too much exposure to the sun will make fiberglass brittle over time. Since you'll be doing most of your boating during the daytime, this will likely be a factor. Salt can get between the layers of fiberglass and then grind away over time. However, this is only a factor if you're boating in saltwater locations.
Various studies have indicated that properly installed and maintained fibreglass roofs can last up to 30 years or more. In fact, some have lasted as long as 50 years. In Europe, a study was conducted to assess the actual lifespans of fibreglass roofs from actual projects.
If the fiberglass insulation is of good quality, installed correctly, and not disturbed, you can expect it to have the same lifetime as the building itself — usually 60+ years.
Many of our stakeholders want to know – how long does fiberglass take to decompose and is it environmentally friendly? In fact, Fiberglass can take up to 50 years to decompose, making it a great long-lasting product and perfect for a number of professional applications.
While not rot in the strict sense of the word, fibreglass boats, especially older boats that used orthothalic resins in their gelcoat and layup are commonly subject to structural deterioration by a process of osmosis.
Not Using Enough Resin
Using too little resin with fiberglass can also be a problem. If you don't use enough resin, the fiberglass may not stick to the surface properly. It can also lead to fiberglass fibers fraying and your final product could be brittle and weak.
The fiberglass used in batts, rolls, and blown-in insulation is an inert material. As such, it doesn't break down or “go bad” on its own. However, this does not mean the material is indestructible.
A soft or moveable transom on a fibreglass boat is an indicator of rot, and can significantly weaken the connection between the boat and the engine. A soft floor on a fibreglass boat can also be an indicator of unseen rot, leading to a boat that is not structurally sound.
There is a more complex form of UV degradation that is exclusive to fiberglass products, however. Constant exposure to subvisible rays of light can cause a weakening of the glass fibers in fiberglass products, causing them to become exposed in a process known as “fiber blooming”.
Fiberglass is vulnerable to damage, but because it's made of plastic, glass fiber and resin, it's probably not going to rot. On the other hand, the wood behind the fiberglass that's often used to give a boat its shape can rot.
Compared to steel and wood doors, fiberglass is a low-maintenance material for doors capable of resisting rusting, rotting, scratches, and dents. While it usually resists warping as well, certain conditions can cause it to crack or warp after a while.
Fiberglass will break down over time for one of several reasons. The sun's heat and ultraviolet rays can eventually cause fiberglass to get brittle. If the gel coat surface is cracked or damaged due to impacts or vibrations, water seeps in through the cracks and damages the structure.
By exposure to ultraviolet radiation, moisture and temperature fluctuations, physical and mechanical properties of composites are subject to different degradation trends, depending on the initial design choices and properties of the fibre/resin materials.
Inherent Brittleness: Fiberglass's composition can predispose it to relative brittleness when juxtaposed with materials such as carbon fiber. This brittleness accentuates susceptibility to diminished impact resistance and heightened proneness to cracking under specific conditions.
Hulls are cut at the waterline before being crushed. Crushed fiberglass without bottom paint goes to concrete company which uses it as a reinforcing addative in concrete. Crushed fiberglass with bottom paint goes to a company which burns it in power generating boilers.
The depth and size of the damage determines what method you should use to repair. For shallow voids, dents, and crazing, you can use a fairing compound. For deeper gouges and holes, you would do a proper FRP repair using mixed resin, fillers, and reinforcement fabric.
With proper maintenance, you can expect fiberglass shingles to last for 30-50 years. That's a potential half-century of use that you can get out of these sturdy shingles! So why does the life expectancy of fiberglass shingles outshine many other roofing materials?
Fiberglass can be tested for in the air and settled dust. The primary air testing method for fiberglass is phase contrast microscopy (PCM), which is also the primary method for testing asbestos in the air.
As fiberglass insulation ages, it degrades, leaving gaps where air can escape. In other words, your heater or air conditioner needs to work even harder to maintain the temperature inside your home. Replacing insulation is a great way to keep your conditioned air inside and lower energy bills.
Fibreglass is known to be a hard-to-break material when it is used to reinforce something else. However, despite the strength of GRP in boats, there are still external factors that could lead to its degradation. When fibreglass is exposed to UV rays, water and saltwater, it wears down faster.
Although not technically classed as biodegradable, fiberglass will eventually break down and deteriorate. Fiberglass will start deteriorating in around 50 years, but it can take hundreds of years.
The potential health effects of fiberglass exposure
However, just as with the chemical flame retardants, fiberglass carries its own set of adverse health effects when it escapes into the environment. For example, airborne fiberglass strands can cause skin irritation and respiratory problems when inhaled.
Fiberglass and fiberglass resin it doesn't rot but if you leave it in the sun the sun will break down the material and you'll have what they call dry rot. It has nothing to do with bacteria or decay it's that the sun and the ultraviolet rays have broken down the fiberglass and now it's starting to fall apart.
People who work with fiberglass or who have worn-out duct work lined with fiberglass in their homes or workplace may have long-term exposure to fiberglass. There is no evidence that fiberglass causes cancer in people.