Do not apply silicone on top of silicone or on top of the old gutter sealant.
Best way to seal old gutter leak.
If possible flush out gutters with a garden hose then allow them to air dry for a clean fix.
Water will eventually find its way.
Do not use the as seen on tv liquefied rubber in a can sealants that promise the world but in actuality work very.
Replace all pieces that make the seam and then finish by re adding the screws.
You need to remove the old caulking.
Lower the uphill piece back into place and press them together for several seconds to make sure you evenly distribute the caulk.
You first need to clean your gutters thoroughly.
The bond will not be permanent and the leak.
Get ready to seal.
Fix the seam seal use the caulking gun to apply sealant on the inner lip of the gutter segment known as the downhill.
Some sealer is water based and may do ok in light moisture conditions but it is best if you check the gutter clean the debris and if its wet wait for a hot day so it will be completely dry.
For sealing and joining lap seams in aluminum or vinyl gutters and downspouts we recommend a permanently flexible and water resistant sealant.
You cannot add more caulking to old.
A waterproof sealing product such as ge clear gutter caulk available on amazon is easy to use.
Simply squeeze into cracks and holes then apply a further coating around the entire gutter joint.