Prepare Gap with Backer Rod

What happens here

The presenter explains the common issue of filling deep gaps, such as around a window, solely with caulk (specifically mentioning 'Tower Tech' as an example of caulk). If the caulk bonds to both sides of the gap, it will expand well but when it contracts, it will push out a 'big bulge of caulking.' To prevent this, a piece of backer rod is introduced. The backer rod is cut to the appropriate length using a knife and then firmly pressed or 'stuffed' into the gap. This creates a proper backing, ensuring the caulk only bonds to the two sides of the joint, allowing for proper movement.

Goal: Provide proper backing for caulk in a large gap to prevent bulging and reduce caulk usage.