I'll Build It Myself (1946)

Edgar Kennedy, never the one to spend money on a project when he can do it himself and spend twice the money with disastrous results, forgoes hiring a builder to add a new room on the family abode, and contracts himself and family members to do the job. Edgar, doing any job is a recipe for failure, and when his ditsy wife, daffy brother-in-law and domineering mother-in-law are part of the construction crew, failure turns to catastrophe.