Removing Old Roof
A lot of people that are planning to lay a new roof are hoping that they can do so, without having to remove the old one first. Unfortunately this is not always the case. So, when do you have to remove the old roof before laying a new one? Generally speaking you would have to remove the old roof if the surface is badly worn due to weather, if the sheathing is rotten, if it has been re-roofed too many times or often – if you have a wood shake roof. Let me tell you a bit more about this.
Worn Roof, Water Damage to Sheathing or Maximum Re-Roofs
So, if your roof surface is badly worn and showing large bare spots with either no shingles or where they are badly curved, you are better off removing it down to the sheathing. If your existing roof has wood shingles or wood shakes and the wood has deteriorated, you would need to remove it as it otherwise will make the new roof look uneven as the nailing base would not be uniform. When it comes to the sheathing, it will have to be removed if you find it to be rotten and this is often the result of water damage. Always remember to strip the old roof and to repair any damaged areas before starting to lay down any new materials. If you find out that your house already have the maximum number of re-roofs allowed, you will have to remove them before laying a new roof surface. Depending on regulations and codes, you are normally allowed three layers of roof on a house: the original roof and two re-roofs on top of that. When it comes to wood roofs, the number is generally only two. If you are unsure of the codes, speak to a local building inspector.
You will generally have to remove a roof with wood shakes before a new one can be installed. The reason for this is that the texture of wood shakes is often too irregular to be able to lay a new roof on to. In order to get a good result, the existing roof surface will have to be flat. If your roof consists of either tile or slate, you are lucky. Both are very durable materials but when they do have to be replaced, the old tiles will have to be removed. The last thing I want to mention is that if you are going from a wood shingles roof to asphalt shingles, it is better to remove the old roof in order to change the sheathing to a spaced sheathing. This means you will have a better nail base for the new roofing materials.