Any advice? Is this sufficient? If not and the builder will not allow additional insulation, etc., what can I do.
COMMUNITY FORUM
I am purchasing a townhouse and asked the builder if I could pay for extra insulation or soundproofing between my townhouse and the one next door. The answer was no. The specs say that the wall will have R-13 kraft faced fiberglass batts. The drywall will be 1/2" thick, field screwed and permieter nailed to framing.
It would be helpful to know why he answered as he did.
Typiocally the fibreglas dows very little to reduce sound transmissions.
A sound barrier wall is called a party wall and is common in apartments and condos. It also incorporates elements of firewalls which are required by code in most places for multiple family dwellings.
This type wall system involves two layers of drywall and of framing and does a fair job of sound absorbtion. It may be that his answer meant that he didn't believe you would need more than that. Or that he had the opinion that you would be wasting money to add more than that.
Suppose the folowing,
You paid him extra to add another layer of SR on your side of the wall buyt were unhappy with the results - little gain for the money. You might then be thinking, "He took my money to provide a soundproofed wall but I can still hear noise from the neighbors" and he might then be subjected to multiple phone calls of complaint. So his refusal to do it may have been in your interests but a defensive move on his part.
But I am only speculating, not knowing the wall detailing you have or his experience with sound walls which are a complex issue.
