So, how do you get started, installing a flat-edged metal valley? Well, whether you are looking to install it on old shingles or on either a new or stripped decks, the first thing you need to do is to lay a 36 inch wide panel of roofing felt along the length of the valleys. I would recommend using a 15 pound roofing felt for this. Once you have done this, nail down the metal along the edges, about 1 inch from the outer edge. Remember not to use any nails in the centre of the valley as this could allow water to go through to the sheathing. However, the nails that you do use, should be galvanised nails and you nail them down every 12 inches or so. If you were to install crimp-edged valleys, I would recommend to use cheats and to fasten them with nails along the edges. The spacing here should also be about 12 inches or so.
The next step should be to spray paint all the metal and this should, off course, match the colour of the roofing material you have chosen. The reason you should do this is to protect the metal but also for appearance sake. It is best to use a metal paint that is rust-resistant. You can buy these types of paints from your local roofing supplier or from one of your local home improvement centres. Before you spray paint them, you will have to clean all of the metal with a solvent before applying a metal primer (and this should be a zinc based one). Once you have done this, it is time for the paint. However, keep in mind that you will most often get a better result by spraying two light coats of paints, rather than drenching it in one heavy coat. You will have to give the paint sufficient time to dry but once that is done, you are ready to finish the valley in one out of three methods. These three methods are: closed-cut finish, open finish and a woven finish.
The finish that you choose to use is generally decided by what type of roof you have. You can use either of the three finishes with an asphalt roof but it would be advisable to use either the closed or open finish if your roof is either wood or tile. I understand that these types of jobs might seem too big and complicated to tackle on your own but this is what you have the professionals for. Whether you are looking for someone to clean your gutters or lay a completely new roof – there is always someone for the job. Best of luck!