With the rains nearly upon us it is probably a good idea to review some of the basics of water control and roof maintenance. One of the most common complaints I hear about water coming off roofs is that the water digs a hole in the garden when it drops from a downspout. This is a problem. There are two classic solutions. One is to hang a chain from the downspout so that the water follows the chain down rather that leaping off into space according to the amount of runoff. This idea works pretty well for most rains, however, there is always the occasional rain which is too strong to be guided by a puny little chain, in which case, the water digs a hole in the garden anyway.
A better solution is to install a pipe, which comes down the side of the outside wall and thus guarantees where the water will go. To accomplish this you remove the downspout and replace it with a short piece of PVC pipe. You then place a 90-degree elbow on the pipe so that it fits snuggly against the wall. Next you put a pipe all the way to the ground. The pipe can be connected to other drainage already in place or can simply empty at ground level onto a rock or small slab of concrete. The pipe can also be plastered so that it appears to be an architectural feature of the wall. This last part may require some thought but it is possible.
The size of pipe to use really depends on the size of the roof area to be drained. I use a six-inch pipe for most applications. Smaller or larger pipe can be used if the amount of water varies. For a small roof or part of a roof perhaps a three-inch pipe would be more than adequate. For an extremely large roof perhaps an eight-inch pipe would be required. I'll leave that up to you.
Every year at about this time I get several frantic calls from people who have suddenly discovered that their roof is leaking and the rain is falling on their heads. I can't say that I blame them for being frantic. Such an event is disconcerting. If a roof is leaking, it is usually because, for one reason or another, the roof has developed a crack. If a roof is cracked, neither paint nor sealer will fix it. Perhaps I should say this more clearly: PAINT WILL NOT FIX A CRACKED ROOF. This is true even if your alvanil or gardener says that paint will fix it. Now, just between you and me, you can try paint if you wish; paint will seal the cracks on the surface of the roof but these cracks don't usually cause rain water to enter your house.
If there is a crack in a roof you need to remove the small tile, which is usually on the roof. (This tile is called azoteo.) Then open the crack up with a chisel so that it is three or four inches wide and remove all the cracked concrete. Then fill in the valley with a mix of cement, sand, and Fester Bond. The Fester Bond makes the new concrete stick to the old. Replace the tile then cover the affected area with an application of Microfest and roof felt.
The way to apply the Microfest is to first paint a section of the roof with a coat of the goop and while it is still wet apply a layer of the felt. It is best to do rather small areas at a time so you can reach over the wet Microfest and place the felt. After the Microfest has dried put another coat over the felt thereby making a felt sandwich. This sandwich is rather plastic and will expand and contract with changing temperatures. It is really a good idea to treat any flat roof with this concoction. Microfest comes in red, black and white. You may have to insist on white and maybe even wait a while but this product is the best I have found for roof treatment in this area.
Mr. Worthington is a long-time resident of the area, a builder and landscape architect. You can contact Mr. Worthington at: This e-mail address is being protected from spambots. You need JavaScript enabled to view it
