Does basement/cellar stairway to 1st fl must have a door?

[Giginw]

Hi all,

My architect said the basement/cellar stairway to first floor must have a door. But a wall dividing the stairway and the kitchen will make the entire space look very small.

I was wondering if there's a code defining this?

Does the code allow hinged floor hatch for the stairway leading to basement?

Thank you!

 

[e hilton]

Is this the same house with the alternating tread stairs to the basement? And the bilco door to the basement? Why would you want a floor hatch in the kitchen floor?

 

[bill1952]

In a cursory search of the IRC, I do not believe a door to basement is required. Having seen houses and plans of houses without a door to basement, it seems likely. I think of several with spiral stairs which are open between first floor and basement.

There could be practical reasons - kids falling for instance - that could make it advisable. I think a trap door or opening with just a rail or part height wall around the open sides would be fine.

 

[RFM132]

If the basement ceiling is insulated to create a thermal envelope, a door may be required to isolate the basement for the energy code.

 

[Saugie53]

If the basement ceiling is insulated to create a thermal envelope, a door may be required to isolate the basement for the energy code.

Just as RFM stated above, (and not knowing which version of the IRC or what amendments your jurisdiction may or may not incorporate) the IRC has residential energy code requirements that need to be met. You have to create a building thermal envelope, most builders don't want to frame out walls in front of the basement foundation (if applicable) and insulate those walls or run continuous rigid foam board up against the foundation and then inslate the remaining space from the top of the foundation to the bottom of the floor sheathing of the 1st floor so instead they insulate the basement ceiling to create the building envelope thereby separating the unfinished/non-conditioned space of the basement from the rest of the finished/conditioned space. If the plan was to insulate the basement ceiling a door would then be required to complete the building envelope. Otherwise if you choose to frame out/insulate the basement walls and create a finished basement you may then get away with not having a door installed. That would definitely be something you want to run by your local building inspector and see what they think.

 

[Giginw]

Is this the same house with the alternating tread stairs to the basement? And the bilco door to the basement? Why would you want a floor hatch in the kitchen floor?

Thank you for remembering my previous questions

Yes it's the same house. I later found out that alternating tread stairs cannot be qualified as a mean of egress. Also my basement is more than 200 sqft limitation. I gave up on it and instead chose to push the 1st floor already-very-small kitchen back to make room for the landing of the basement stairway. So I don't have to knock down the foundation wall.

As to the egress door, I chose L shape to allow more comfortable walking. I saw that bilco door is around $1k, for the same price I can probably install a clear freestanding sunroom/canopy to protect the drainage and waive railing?

If I can install a hatch door on the floor and railing, instead of regular wall and door, then the space from basement to the 1st floor kitchen will look more open

 

[Giginw]

In a cursory search of the IRC, I do not believe a door to basement is required. Having seen houses and plans of houses without a door to basement, it seems likely. I think of several with spiral stairs which are open between first floor and basement.

There could be practical reasons - kids falling for instance - that could make it advisable. I think a trap door or opening with just a rail or part height wall around the open sides would be fine.

Thank you! That's what confused me as I saw so many basement stairways with no door or any sort of cover, but my architect insisted on having a door.

 

[Giginw]

If the basement ceiling is insulated to create a thermal envelope, a door may be required to isolate the basement for the energy code.

I was planning to insulate the whole basement with maybe R19 or even higher batts since foam insulation might be too expensive.

The basement ceiling is only 7 ft high. Originally I wanted to paint the ceiling and exposed pipes black to give it an industrial and modern look. But my architect said exposed ceiling won't pass the inspection.

So I think I'll insulate the ceiling and walls together. Insulation is important to keep the electricity bills reasonable as I'll get rid of gas completely and use ductless mini split units for whole house heating and cooling.

 

[Giginw]

Just as RFM stated above, (and not knowing which version of the IRC or what amendments your jurisdiction may or may not incorporate) the IRC has residential energy code requirements that need to be met. You have to create a building thermal envelope, most builders don't want to frame out walls in front of the basement foundation (if applicable) and insulate those walls or run continuous rigid foam board up against the foundation and then inslate the remaining space from the top of the foundation to the bottom of the floor sheathing of the 1st floor so instead they insulate the basement ceiling to create the building envelope thereby separating the unfinished/non-conditioned space of the basement from the rest of the finished/conditioned space. If the plan was to insulate the basement ceiling a door would then be required to complete the building envelope. Otherwise if you choose to frame out/insulate the basement walls and create a finished basement you may then get away with not having a door installed. That would definitely be something you want to run by your local building inspector and see what they think.

Thank you so much for the information!

Yes I plan to insulate the whole basement and make it look like a vintage bar/movie room. It will be a big open space and not legally rentable.

I'll use ductless mini split for heating so the water pipes don't burst in winter. Also two electrical tankless water heaters will be installed for two family so insulation will protect those from cold winter

 

[bill1952]

But my architect said exposed ceiling won't pass the inspection.

Well, I never heard of that. Would love to see that code reference.

 

[ADAguy]

Love DIY'rs

 

[Mr. Inspector]

Ask your architect for the code sections that say the ceiling must be covered and that you need to I have a stairway to the basement

 

[mtlogcabin]

It looks like exception 4 will work for you if the floor joist are a minimum 2" X 10"

R302.13 Fire protection of floors.
Floor assemblies that are not required elsewhere in this code to be fire-resistance rated, shall be provided with a 1/2-inch (12.7 mm) gypsum wallboard membrane, 5/8-inch (16 mm) wood structural panel membrane, or equivalent on the underside of the floor framing member. Penetrations or openings for ducts, vents, electrical outlets, lighting, devices, luminaires, wires, speakers, drainage, piping and similar openings or penetrations shall be permitted.

Exceptions:

1. Floor assemblies located directly over a space protected by an automatic sprinkler system in accordance with Section P2904, NFPA 13D, or other approved equivalent sprinkler system.

2. Floor assemblies located directly over a crawl space not intended for storage or for the installation of fuel-fired or electric-powered heating appliances.

3. Portions of floor assemblies shall be permitted to be unprotected where complying with the following:

3.1. The aggregate area of the unprotected portions does not exceed 80 square feet (7.4 m2) per story.

3.2. Fireblocking in accordance with Section R302.11.1 is installed along the perimeter of the unprotected portion to separate the unprotected portion from the remainder of the floor assembly.

4. Wood floor assemblies using dimension lumber or structural composite lumber equal to or greater than 2-inch by 10-inch (50.8 mm by 254 mm) nominal dimension, or other approved floor assemblies demonstrating equivalent fire performance.

 

[Mr. Inspector]

Is this an existing building or new?