# Which wood best for loft floor in tiny house



## Rosss (Jan 29, 2018)

I will be building a tiny house that will have lofts at both ends. The span will be about 8'8" from one side to the other. I am planning to used boards I mill for the floor of the loft. I want to do the span with support only at the ends where the walls are. i will do some research as to how thick I need to make the boards to do the span.

I have access to spruce, pine and poplar logs that I could mill for this. Any suggestions as to what to choose? I am asking mostly from an ascestics what will look best
angle. The floor will be the ceiling of the kitchen as well as the loft bedroom floor.

Also asking if there are any issues that may arise using any of those woods for this purpose?

Here is a picture to give a visual on what I am talking about.

Thanks


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## ChoppyChoppy (Jan 29, 2018)

Spruce or pine. 2x6 16"oc with 1 bys sheathing it.


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## Rob Stafari (Jan 29, 2018)

8'8" is an awful long way for flooring to span on its own if I'm reading you correctly. Better off milling your own timbers for support of a thinner tongue and groove flooring.


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## Rosss (Jan 29, 2018)

Rob Stafari said:


> 8'8" is an awful long way for flooring to span on its own if I'm reading you correctly. Better off milling your own timbers for support of a thinner tongue and groove flooring.



Yes you understood correctly. 

I know that the building code here allows for a span of about 8 or 9 foot with I think 2x8 tongue and groove if screwed/glued together so that stress is passed to the neighbouring boards. I haven't done my research yet but I would think that I can either compensate for the lack of toungue and groove by both making the boards wider and thicker. 
Part of the desire for not having beams for support is that it is being built on a trailer there is a maximum height that is a factor, so saving a few inches is part of it.


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## Rob Stafari (Jan 30, 2018)

I think for the relatively small amount of flooring it will be that I would make some backyard tongues and grooves with the table saw and go with the smallest dimension you're comfortable with to save weight. Even if you go thicker and wider, wood by nature will move and likely not move the same as the piece next to it. Even if it doesn't stay perfectly straight, I'd want them to stay in the same plane relative to one another.


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## paco_06 (Jan 30, 2018)

Poplar will be best, it's stronger than pine or spruce. I would use a minimum of 3" thickness. You need to use some type of dowels if you're not gonna tongue and groove them. I'd say on 12" centers. Use glue too. May have to use a 2x6 edge ways to support the last board towards the center of house

Sent from my XT1030 using Tapatalk


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## Deleted member 117362 (Jan 30, 2018)

Believe you need to state expected load in that loft area and over build. You can find span charts for various loading. Fell through our ceiling once, no fun.


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## Rosss (Jan 30, 2018)

The expected max load is probably 500 lbs - 3 people and a bed. 
I think building code is to plan for 40 pounds per square foot? 3600 lbs?
The max deflection allowed by building code is 1/3 inch.

All the wood span tables i found are for joists in typical orientation with the widest part up and down, so still looking to figure out the spans for something like a 2x12 on it's side.

I think this is easy enough to build, in the carefully think it through and do a bit of research, but figuring it out to building code, with home milled, ungraded, lumber is going to take some research.

Also realized that if I put the bathroom under part of the loft I get support for the loft in that area.


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## Mad Professor (Jan 30, 2018)

How about adding a beam (6 X 6" ?) at mid span with a couple of posts on each end. Could do that mortise and tenon with a couple of small knee braces for a rustic look.


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## ChoppyChoppy (Jan 30, 2018)

Poplar is not stronger than spruce. It's not even structurally rated.

A 2by on it's flat will deflect too much. 3 people and a bed... I'd figure more than 300lbs. A queen bed, box spring and mattress will be close to that on it's own.

30 or 40 lbs per sq ft is about right. so an 8x8 loft would need to support around 2000-2500lbs.

If it were me building, I'd probably do 3x6s and pin them together. BUT who knows if that could meet code. Usually when the code is strict like that you need engineered prints anyhow.


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## rarefish383 (Feb 3, 2018)

Nice Tiny House. I like White Pine. I made this dining table out of beetle riddled White Pine milled off my property. Of course you wouldn't use boards with bug holes for the flooring. This table has inlaid hinges and folds up against the wall, with a paddle to hold it in place. Turning the dining room into a bunk room at night, Joe.


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## kimosawboy (Feb 3, 2018)

If your tiny house is on a trailer, any 'code' does not apply. If you are building with permits then you will have to get an engineer involved. If you are just building for yourself, no permits.... just go with 12/4 spruce drilled and doweled like someone else mentioned.(if thats the best you have)

G Vavra


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## Odog (Feb 3, 2018)

2x10 spruce or 3x8 spruce should be sufficient. Both line and spruce are structurally sound. You could tongue and groove both 2x or 3x to give it more stability, or you could make a ship lap type joint with a rabbiting bit and a router. Then glue the joints. Any way you decide, the boards should be adhered to each other to give the span more strength.


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## Marine5068 (Feb 11, 2018)

Rosss said:


> I will be building a tiny house that will have lofts at both ends. The span will be about 8'8" from one side to the other. I am planning to used boards I mill for the floor of the loft. I want to do the span with support only at the ends where the walls are. i will do some research as to how thick I need to make the boards to do the span.
> 
> I have access to spruce, pine and poplar logs that I could mill for this. Any suggestions as to what to choose? I am asking mostly from an ascestics what will look bestView attachment 629121
> angle. The floor will be the ceiling of the kitchen as well as the loft bedroom floor.
> ...


If I'm seeing the example correctly and there's a beam at the wall edge (inside end where walls stops) then why don't you just run joists under where the floor above will be?
That would be conventional floor structure and then you can put any kind of flooring on it. 
You can make them 2x6 at 16" o/c they can span up to 10 feet using pine, spruce or fir.
I would go that route, and the home-cut joists would look fantastic viewed from below with hardwood flooring exposed too.
Then all codes are met and you still get the look of exposed flooring from underneath, no matter what floor material you decide. I like Oak flooring myself.
Just an idea from an Architectural Technologist and building expert with 30 years experience in solving these designs and such, but up to you of course.


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## Rosss (Feb 11, 2018)

Marine5068 said:


> If I'm seeing the example correctly and there's a beam at the wall edge (inside end where walls stops) then why don't you just run joists under where the floor above will be?
> That would be conventional floor structure and then you can put any kind of flooring on it.
> You can make them 2x6 at 16" o/c they can span up to 10 feet using pine, spruce or fir.
> I would go that route, and the home-cut joists would look fantastic viewed from below with hardwood flooring exposed too.
> ...



Would totally do that if I was building a permanent structure that would not be moved. It would look fantastic! and I have noted that for when/if I build a permanent place.

The issue for the tiny house is that it will be moved on a trailer. I don't have a permanent place for it, like land I actually own, so I need to build it with a maimum external height of 17'6" so basially 17 feet including the trailer and I am trying for the loft to be high enough to stand up in, rather than the typical tiny house loft that is sit up or crouch in only.

Once I start adding stuff up it gets to where the extra 6 inches for joists is something I don't want to give up if I don't need to.
The building is not going to meet all the local building codes but the more codes that are met in the build the more likley it will be that the building can slide through the various possible hoops that may come up during it's life time or use.

Currently the city I live in is moving towards allowing tiny houses of some types, but that is a year or two off and that could have a range of what is allowed from simply a conventional house but with less than the current min allowed sq ft to something temp of screw piles connected to municipal services to a tine house on a trailer or?

I was more concerned about which wood would look best when I started this thread than the structural bennifits that might come with the different species. If I am not too worried about wight I can ultimated just make the boards thicker.

A friend did the main floor of his kitchen in his tiny house out of tounge and groove 2 inch boards and they apparently meet code on an 8 ft span when screwed and glued togather. I will consult with him more in the near future to see where he got his info. and such.

Here is his house.


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## Marine5068 (Feb 11, 2018)

Rosss said:


> Would totally do that if I was building a permanent structure that would not be moved. It would look fantastic! and I have noted that for when/if I build a permanent place.
> 
> The issue for the tiny house is that it will be moved on a trailer. I don't have a permanent place for it, like land I actually own, so I need to build it with a maimum external height of 17'6" so basially 17 feet including the trailer and I am trying for the loft to be high enough to stand up in, rather than the typical tiny house loft that is sit up or crouch in only.
> 
> ...



Sorry but I didn't know it was a mobile home on a trailer.


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## Rosss (Feb 11, 2018)

Marine5068 said:


> Sorry but I didn't know it was a mobile home on a trailer.



I totally got that  I appreciated your response. It hadn't occured to me how beautiful cuttin gmy own floor joists would be, looking forward to doing that at some point.
If you have any ideas or feedback your welcome to share. I will likley make a thread once I start the build, hopefully in a few months.


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## tomsteve (Feb 18, 2018)

8'8" side to side- what is it front to back? can you run the floor front to back? i


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## capetrees (Feb 18, 2018)

thicker is better regardless of width


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## capetrees (Feb 18, 2018)

or maybe make something like plywood, two or three thinner layers, sandwiched together, glued and screwed, each layer perpendicular to the layer below?


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## ChoppyChoppy (Feb 18, 2018)

I'd imagine weight is also a concern? 

I don't think a 17.5ft height being too hard to stay under. If the trailer is 2ft tall, that gives 15.5ft to play with. 7ft ceiling, 6" floor.

What is the max height coming from? Here we have to be under 15ft. Over needs permits and pilot cars.


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## kimosawboy (Feb 19, 2018)

You might want to double check your legal height limit....or your math 
Here in BC max is 4.15 meter (13.6') , I dont see your province adding an additional 4'??


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## Rosss (Feb 19, 2018)

kimosawboy said:


> You might want to double check your legal height limit....or your math
> Here in BC max is 4.15 meter (13.6') , I dont see your province adding an additional 4'??



The height limit here to be on the road with out a permit is 14' 6" 
The width limit with out a permit is 8'6"

17'6" is the max height with out needing a complicated permitting process. Below that height you are supposed to have permits and such but you will fit under any recently engineered over head. Over that and they design your route and you have to have some fairly complicated caravan of 
I don't expect to move the tiny house more than once every 3 or 5 years so I would rather have extra width (building to about 10'3" and extra height and endure a bit more process to move. 
The permits are not expensive, just a bit of effort to arrange.

A few blocks from my house they build giant pressure vessels and they have to pull all the overhead electric wires and turn the streetlights sideways so they don't over hang the roadway when they move those. It is quite amazing to see something of that size moving down the roadway. I think they max out at about 5mph on the whole trip with those.


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