There are several ‘levels’ of roof replacement. The easiest is simply to replace the visible part of it. This involves removing all the shakes, tiles or whatever the roof is finally covered with. Under that, lies a number of other layers, each performing a specific function in the protection of your home. Let’s look at what each function serves, and try to get an idea about just how much of the roof should be replaced:
The supporting infrastructure of your roof
We’ve all driven past homes or other buildings that were under construction. One of the most important parts of a house is the wood, steel or other supporting structural material that provides the framework for the complete protection from above. Rafters are placed in parallel to one another, and will provide more than enough strength to hold all of the materials that will soon be placed on top of it. Hopefully, this part of your home will last for the lifetime of your house, and never have to be replaced. Sometimes, though, a neglected leak, over a long period of time, can eat away into this infrastructure, and a problem is not discovered until a lot of damage is done. The best way to prevent problems with this part of your house is to avail of regular roof inspections. Most roofing companies offer free or almost free roofing inspections, so this is a super economical way to keep your roof in tip top condition by preempting problems long before they cost you serious amounts of repair costs. A roofing company will always look at ventilation. Is enough air passing through your roof so that, in the event of minor leaks – a few drops here and there – no real damage will be done because it will dry out quickly. Closed, sealed attics, for example and the perfect place for moisture to become trapped and to do their damage slowly and surely. Get roof inspections every two or three years and you will never regret it. What’s the worst that can happen? The roofing company finds nothing, and you’re good for another few years!
The plywood or particle board covering the infrastructure
Again, you’ve probably seen this in your neighborhood at some point or another. On top of the rafters and other supporting beams is the layer of plywood or similar wood sheeting. It covers the infrastructure below it, and provides a base upon which every above it sits.
Sometimes, a leak will reach this layer of plywood. It will damage the layer slowly, and you may not notice anything inside your house if the leak is not bad enough to make the problem obvious. This is when the wood remains damp for weeks, months or even years. The longer it remains damp, the more damage it does, and eventually will fail completely, collapsing down inside the attic space and beyond. A roof inspection – which usually involves a walk over the roof itself – will give the impression of ‘softness’ or ‘sponginess’, the tell tale sign of a roof leak problem that has gotten out of hand and will need more than just tile and waterproofing replacement.
At least one layer of waterproofing on top of the plywood
Now comes the layer of waterproof plastic sheets. These might be as simple as plastic sheeting similar to heavy duty bin-liners, but they have a specific purpose and design which regular bin liners will not perform. They must withstand years – even decades – of abuse from Mother Nature, and must reach exacting manufacturing standards and regulations so that the consumer gets all the protection they need from this invisible but essential component of your roof. In many ways, it’s the most important layer. That’s because, even if there is a flaw in either what’s above it or below it, this layer will stop water, plants and critters from getting into your home.
Before the next layers go on, this waterproofing layer should, in theory, protect your home from the elements. Exposed to the sun, rain, ice and perhaps falling objects is not what it was designed for, but it should at least provide a complete waterproof barrier before the next layer goes on. It’s applied in rolls, usually, and each successive roll overlaps the lower one, providing some extra insulation.
This material is actually nailed to the plywood layer under it. You can’t use any ordinary nails for this. Special roofing nails are used which keep the waterproof seal of the plastic while still going through the plastic. Using ordinary nails will simply give you thousands of holes through which the rain can travel.
The roofing tiles or equivalent covering
The final layer finishes the project. It’s what everyone sees when the work is all done, and provides a different type of protection to all lower layers. The tiling can withstand the impact of everything from acorns to small branches and any other debris that can find its way to the surface of your roof. Even a level of high wind, snow, frozen ice and torrential rain can be resisted by a well installed set of roofing tiles.
Today, there are thousands of varieties and combinations of roofing tiles – both real wood and synthetic – to choose from, and many of the manufactured ones on the market now will last longer that the home owners themselves. Synthetic roofing tile, although impressive in their longevity, flexibility and robustness, still need to be inspected once in a while. Nothing lasts forever, and a simple breakage or crack can let water begin to get in behind those tiles. The water barrier provided by the waterproof under layer has its own lifetime age, so it still needs to be inspected too.
Replacing a roof, if it is just the tiles you are replacing, is relatively simple. Any decent roofing company will be able to quote you a fixed price for that. It will include the waterproofing underneath those tiles, as that layer will have aged and fatigued at least as much as the tiles sitting on it. Less common is when the plywood needs to be replaced, but it still only begins to get expensive when the roof infrastructure needs work.
Regular roof inspections is the way to go!