Things You'll Need
1/8-inch masonry drill bit
2-inch anchor bolts or 1 1/4-inch concrete nails
1/ 2-inch sheet metal screws
In order to get a better understanding of how to attach a downspout to stucco siding, the basics behind what stucco siding is and how it is applied should be understood. Stucco is normally applied to two different types of surfaces. It can either be used to cover a masonry wall such as block or it can be used to cover a regular stud frame wall. Stucco is made from a mixture of sand, cement, lime and glue. On a block or masonry wall, it is simply spread over the face of the wall and the glue helps to adhere the stucco to the surface. For a frame wall, a backing of black roofing paper or Styrofoam sheets are used with a layer of wire mesh over the sheeting and is nailed over the wood studs. The stucco is then applied over this backing and allowed to dry.
Determine what type of wall you have behind your stucco framing. If it is a frame wall, locate studs behind where you will be attaching your downspout. It will make a difference in the method you use to attach the downspout to the stucco.
Place a downspout anchor bracket on the wall where you want to attach the downspout to the bracket. Use a pencil to place two marks on the stucco wall where you will be attaching the bracket to the wall with nails or screws.
Drill two 1/8-inch holes in the stucco wall with a drill and 1/8-inch masonry drill bit where you will be attaching the bracket. If you are drilling into a masonry wall, only allow the bit to go about 1/2-inch into the wall. If you are drilling into a frame wall, allow the bit to go all the way through the stucco backing.
Place the bracket on the stucco wall and secure it to the wall. If it is a frame wall, use 2-inch anchor bolts to secure the bracket to the wall by tapping the bolt through the pre-drilled holes with a hammer and using a screwdriver to tighten the bolts. If you are nailing into a masonry wall, use a minimum of a 1 1/4-inch concrete nails and use a hammer to drive the nails into the wall to attach the bracket. Note: Tap the bolts or nails gently with a hammer to keep from knocking stucco off the wall.
Secure the downspout to the bracket by drilling sheet metal screws through the bracket into the downspout on both sides.
To keep the stucco from cracking when you are drilling the pilot holes, place a piece of scrap plywood with a pre-drilled hole the size of your drill bit over the stucco wall area that you are going to drill and then drill through the hole.