Ask the Architect

Adding to the attic

Posted

Q. A few contractors have looked at my attic so I can finish it for more bedrooms and a family room. The 1920s house has a very large attic with stairs to the second-floor landing. The attic stairs are much steeper and narrower, and the contractor says the walls will need to be taken down and wider and longer stairs put in. Is this necessary? The stairs are already there, and even though they’re steep, they work. Also, one of the contractors said that the horizontal 2x4s going across the attic, which are too low to walk around, could be removed or raised. Is that true? He said we could put them higher and add more so we can add finished wallboards to them. Do you agree, and is there anything I should know about doing this before we start?

A. Good thing you asked before you started. Instead of starting, you need to stop and take a few steps back. What you’re describing has multiple issues that you have to address.
First, your state building code doesn’t allow the occupancy of a third floor in a single-family, wood-framed dwelling. This is because of the many dangers involved in surviving a fire at that level. In the process of getting the permit to occupy a third story, which you left out of the description of your investigation, you would need to have a licensed architect or engineer prepare plans that include specific methods of escape, including the correct size and number of windows, distances to exterior and interior levels below to escape to, sprinkler locations along the entire path of travel to get out of the dwelling, heights of ceilings and fire-rated materials to be installed. This is because, as I have often written, the chances of surviving a fire in the third floor of a wood-framed dwelling are statistically remote, only 5 percent. That means you or your loved ones could be among the 95 out of 100 who will die from smoke inhalation or burns.
The plans for a finished third story are submitted to both your local building department, which will rightfully reject them, and to the State Codes Division for a public hearing, where your case will need to be represented by a code-knowledgeable professional. I have seen people represent themselves, which generally doesn’t go very well, since safety is the reason for the codes, and there are many laws and standards that the average owner is unaware of.
The stair access must be 3 feet wide, and the tread must be at least 10¼ inches, while the risers cannot exceed 8¼ inches. The horizontal 2x4s you described are collar ties, and they serve the important function of holding the roof together, especially in high winds and under snow loads. Moving or removing them can be dangerous. The higher up, the less effective, and without first calculating several factors, it should not be done.

© 2022 Monte Leeper. Readers are encouraged to send questions to yourhousedr@aol.com, with “Herald question” in the subject line, or to Herald Homes, 2 Endo Blvd., Garden City, NY 11530, Attn: Monte Leeper, architect.