The roof of a house has a double importance: it affects the overall aspect of the building and, from a technical point of view, it provides protection against the elements. Subject to the direct action of the weather through the large surface that comes in direct contact with the environment, the roof must ensure the thermal comfort to the entire building, and this cannot be achieved without being waterproof, properly insulated and in good shape. A damaged roof can compromise the entire construction, therefore it must be replaced promptly, when the time comes. But how can you know that you need a new roof and simple repairs will not do anymore? The most obvious indicator is the roof`s age.   Roofing materials have various levels of resistance and come with different warranties as do siding materials. For example, if you have an asphalt roof which is over 30 years old, then you should consider replacing it soon, even if it still looks good from the ground. Asphalt shingles are designed to last 20-30 years, therefore a 40 years old roof is surely weakened even if it may not be so obvious. Of course, you must not replace immediately a roof that is still functional, but you must be prepared to replace it soon, as it will not take so long anymore until the first problems appear.  Of course a professional Lansing siding contractor is always the best choice to ask when deciding which materials should be used in your area.