Most vinyl gutters come with a smooth finish and coloured pigment that was added to the vinyl during the extrusion process. However, in locations where vinyl gutters receive direct sunlight for much of the year, the colour can fade. In addition, some chemicals or exposure to freezing temperatures can cause discolouring. Fortunately, vinyl gutter is paintable, allowing you to add a fresh look to your home in a weekend. Because the surface of vinyl guttering is smooth, some preparation is needed before painting.
Remove the downspouts from the house. It's easier and less time-consuming to paint the downspouts when they rest horizontally on two or more sawhorses. This eliminates the need to tape off the siding beneath the downspouts. Most downspouts have a PVC clamp that matches the colour of the guttering. Save all the clamps and the screws in one box for safekeeping.
Wear old clothing when cleaning and painting your guttering. In addition, wear protective eyewear. You will be looking upward, and even a little drip of cleaning solution or paint could damage your eyes and your vision. Long sleeves and silicone-type gloves are necessary when working with a liquid sanding solution.
Clean the guttering and the downspouts. After years of hanging on your home, the guttering will collect dust and grime that settles into crevices. Use a large nylon scrub brush and dip it in a bucket filled with warm water and trisodium phosphate (TSP), which is sold at hardware stores. Allow the guttering to dry completely.
Brush on a thin layer of liquid sanding solution and wipe it off with a clean rag. Work on a lineal 3-foot section of guttering at one time. Pay special attention to crevices where the liquid pools. The solution removes the exterior gloss from the surface of the vinyl, allowing the new paint to adhere.
Add a flex additive to your paint by measuring the additive as directed on the bucket and mixing 1 gallon at a time. Vinyl has a high contraction and expansion factor, and paint without flex additive will crack and peel.
Use a good brush when applying the new paint to your guttering. If you have a spray gun, you may spray the downspouts while they lie on the sawhorses, but don't spray guttering that is still attached to the house. When brushing on paint, a short wide, natural bristle brush will leave a uniform finish.
Apply at least two thin coats of paint to the guttering, allowing the paint to dry between coats. If you're spraying the downspouts, three or more coats may be required for adequate coverage.
Paint on a wind-free day to prevent dust from marring the finish of your new paint job.
Use a ladder with care, never positioning it on an uneven or unstable surface. Never stand on the top rang of a step ladder.