BIG floor.

[pizza]

Hi,
I've been asked by a local artist to lay a hardwood floor in his gallery.
The floor area to be laid is 176m2 (22x8)
The room is a basic oblong with a stairwell at one of the long ends.
The north/south measurement is 22m and the client wants the floor running east to west.
My question is about expansion gaps.
I am able to ensure a gap around the exterior of the floor with the exception of the stairwell. However will i need to leave one or even two expansion gaps along the north/south (across the grain) run?
I have already prepped the room ready to order the flooring, and have added extra joists meaning I now have 25cm centres. The floor when fitted will be secret nailed with 2inch portanails.
Seeing as there will be works of art (?) on display the room will have a fairly constant temperature/humidity.
many thanks for any replies.
Pizza.

 

[WoodYouLike]

What type of hardwood flooring? Width of boards, wood-species?

 

[pizza]

evening and thanks for your reply.
the floor will be 90x25mm european oak (polish?) and random lengths from 45cm to 120cm. on these planks the tongue is 8mm thick and is placed centrally on the thickness. The sample piece shown to me had no relief cuts on the back face.
thanks,
Pizza

 

[WoodYouLike]

OK, so the total width of the new floor will be 22 meter (installing parallel to the shortest wall).
This means you'll have to turn direction in the middle, using a "feather" - loose tongue and leaving at least 5cm gap around the perimeter of the whole floor.

Because you're going to secret nail and turn direction in the middle of the room, you'll have to start in the middle of the room with your installation.

 

[pizza]

Thanks for your reply.
any suggestions on how to finish the floor around the top tread and around the banisters, as the staiwell is almost 5m long along one of the short walls, meaning there is no way i could have a 5cm gap at this end. Normally, I would leave a larger gap at the opposite end and finsh 10mm off the bottom rail of the banister and cover that with a cover strip. However I've never laid a floor this size before and want to gather as much info as possible before I start.
Also, as an aside, it has been suggested that as it's a gallery and will be subject to heavy traffic, to lay a bead of siicone on the joists prior to laying. The argument being that if the floor does fail, it will be less likely to squeak?
Thanks again,
Pizza

 

[WoodYouLike]

Never leave different size gaps, wood doesn't know it should only expand to where you left the bigger gap.
Now, if they would switch to wood-engineered flooring, many of your problems would disappear.