Boxing in Understairs

[sadams]

Hello all,
I'm looking for a bit of advise please. I'll explain the problem, show you how I think I might be able to fix it and you can all tell me how wrong I am and tell me how it should be done.

Problem:
I'm hoping to block in under my stairs, to create a large cupboard, I need a reasonable size door since I need to store big things in there (like musical instruments). See pic for shell with dimensions (even a rubbish picture speaks a thousand words):

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• sadams
• 25 Sep 2008
• 2

The issues: Although this needs to be a solid structure I want to damage the laminate flooring as little as possible. The house is in a shared ownership scheme (with a housing association) so I have to be careful about things like that.

My Idea:

So my idea is to use two pieces of 2440x1220x18 MDF board and basically panel it all in. Cutting a door out and putting it on hinges with a small subtle handle, I would then finish with a white gloss paint to match the stair case...again, see bad picture(colours for clarity only):

Untitled

• sadams
• 25 Sep 2008
• 1

My Questions:
Is this a good idea? (is there an obvious alternative)
I'm good at DIY and woodwork but have never done anything that actually requires "Structural" type work. Since this is almost a temporary wall type project (but don't want to go down the stud wall route)

If this is a reasonable plan, what is the best way to secure the wall/cupboard? Is there a clever way to do it which would allow the least amount of flooring fixtures?

Please share your ideas and ask if I need to clarify further

 

[xerxes]

If you're removing any structural timbers from under the stairs, it's important to put something back in their place; a plywood bulkhead is a good way to do this. However, it doesn't look as if that applies in your case.

I would plan to divide the doors you're using to close off the cupboard so that they don't obstruct the hallway when they're open. Piano hinges are useful for this; a wide door can then be folded back on itself.

A mistake I've made in the past is to make doors with an acute angle at the top corner. This makes them impossible to open, unless a chunk of timber is taken off to provide clearance. A flat-topped door works fine, of course.

It might be worthwhile putting together the main items you want to store, and arrange shelving or dividers to suit.

And don't forget to allow clearance at the bottom of the doors, so that they open and close easily over the floor in front, especially if the floor isn't level.

 

[^woody^]

You wont be able to just use a sheet of MDF. You need some sort of frame or it will wobble about and the sheets warp.

Also, that door is going to be annoyingly and impractically tiny.

Consider having a taller, or even full size door, but with the top corner chamfered to the stair angle

If you do use MDF, you will need a frame of 2x2 or 2x1. You could get away with 2 or 4 floor fixings, and these could be filled later if the frame is removed.

Also consider how you will get good hinge fixings into a heavy MDF door

Think about lighting.

And don't store any flammable or suchlike things in this cupboard under the stairs

 

[sadams]

Thanks for all the advice, really appreciated!

1. Nothing being removed so no need for supports etc.

2. The Door:

Ok so here is where the main trade off is.
I want the door to be big enough to get stuff in (it maybe too small in the picture above) but as ^woody^ said it will be pretty heavy. In the picture above I made it as big as possible but with out having to have an angle in the door (since this would make opening/closing hard). A trade off may be to cut one corner off (not all - see the picture below) which would mean that the far left corner is still flat so would make the opening angle less of a challenge. So now I have the problem of hinging this heavy mdf door onto a temp mdf wall (sounds scary) but I'll have a look at what hinges are available (any suggestions?)
My drawings are all to scale and the door is the width of a standard internat door, does it now look too heavy?

3. The Frame
Also see in the picture below a suggestion for a frame. I've heard that if I built the frame out of a different wood type (i.e. timber instead of mdf) without balancing it with an identical frame on the opposite side (not possible) then it can actually make warping worse as the two wood types expand/contract at different rates with heat/humidity. Would it be feasible to build the frame out of the same MDF since I would have quite a bit left over?
Would I be better building the whole thing out of a different material (i.e. not MDF) to reduce the chance of warping?

4. Floor fixings: What is the best way to fix this to the laminate floor? I think it might be concrete under the laminate?

5. internal shelving: Still need to sort that out, just making sure the entire project is possible first.

6. "Also consider how you will get good hinge fixings into a heavy MDF door" Any advice on this?

7. lighting, thankfully the hall way light is right outside the door so that will be sufficient, I don't fancy messing with electronics anyway!

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• sadams
• 26 Sep 2008
• 1

 

[^woody^]

A door pivots from its hinge. There is no problem with chamfering a corner- it will still open and close.

The short answer to this is to bear in mind that some sort of timber frame should surround the MDF panel to provide stiffness - you can decide what is required. There will be no issues with differential movement of the two materials.

For the door, you will get poor fixings in MDF, so perhaps a timber strip is required to the hinge side to provide a better fixing?

You need to fix to the concrete - brown plugs will do

 

[sadams]

Thanks for all your help, I think I'm all clear now. Sorry about all the questions, as I said I'm good with my hands but this is a new area for me so I just want to make sure I get it right, so thanks.

 

[awbcm]

The way I see it you have a choice of 3 methods of fixing the MDF panel to the stair string;

1/ Screws and the use of pocket holes, with the joint disgised with a shadow grove.

2/ Timber batten and cover mould to disguise the joint.

3/ MDF fixed to the face of the string with decorative edge, and timber batten.

You can have a pair of doors this will reduce the weight and you will be able to use normal push to close concealed cabinet hinges (like those that are used on kitchen and wardrobe doors). I would recommend that you use a minimum of 1½ pairs per door. You will need hinges that are suited for inset doors not overlay doors.

I would also go for option 3 as the stair string is used as the door stop thus being a lot easer to fit.

See drawing

Don’t use a timber framing around the internal face of the doors there is no need just look at the mass produced wardrobe doors. Do they have timber frame work? Plus if you glue a timber frame to one side only the door will warp due to there being no balancing frame.

 

[big-all]

asuming you are using 12m mdf
you can if your careful and do a pilot hole screw piano hinges to the face of mdf without any problems
you can do the same to the edge but your hinges will protrude by around 6mm
why not have the minimum practical door and an easily removable section for the occasional bigger item!!

 

[awbcm]

Forgot to mention but if you use concealed cabinet hinges then there will be no need for door catches.

You can al so have a look at this thread

 

[sadams]

Thanks for all the help everyone, I really appreciate it. I have just one final Question...if you don't mind?

some sort of timber frame should surround the MDF panel to provide stiffness - you can decide what is required. There will be no issues with differential movement of the two materials.

if you glue a timber frame to one side only the door will warp due to there being no balancing frame.

So my understanding from this is that there is no need for a frame on the door since it is small therfore nor needing the strength and will warp it, but a frame needs to be put on the Main panel for strength, I'm assuming it wont warp since it is attached to wall/floor unlike the door which is only attached via hinges.

Thats all fine but I was wondering if someone could just clarify (for future reference/not just this project) when a frame is/isn't needed. Is it simply that doors aren't fixed on all sides so are more likely to warp or is there more to it than that. Are frames built from certain materials more likely/less likely to cause warping? is softwood/hardwood even a strip of MDF recommended as frames...I was just going to go with pine.

Thanks again for all the help especially the very useful diagrams, much appreciated!

 

[^woody^]

I don't agree that a frame on one side of the door will cause it to warp

The property will have relatively stable humidity levels, and presumably the timber and MDF will be decorated.

In any case, the framework is going to be so small in context, that any expansion/contraction due to moisture absorbency differentials is going to be insignificant

 

[awbcm]

For what it may be worth I am giving you the benefit of my experience; I have been professional cabinet specializing in bespoke cabinetry for the past 35 years. I also produce guides for the DIYer.

Try an experiment take a piece of MDF and glue a piece of timber to one side, within a couple of days the door will warp.

It’s the same thing if you apply a laminate or veneer to one side only of a man made board or solid timer it will warp. Your door will need a balancing frame of the same section size.

If you laminate two pieces of MDF, plywood or timber as long as they are both the same thickness it will not warp. But if you laminate say a 18mm MDF panel to a 12mm MDF panel then it will warp, it needs a balancer of 12mm MDF on the opposite side.

This is one of the first things you learn in your apprenticeship and It has nothing what so every to humidity.

You can screw or nail a soft or hard wood frame to the MDF and it may not warp, but if you use glue it will. You will be putting the panel under tension.

On top of that the size of the door doesn’t justify a frame anyway so why put one on?

 

[^woody^]

It has nothing what so every to humidity.

What has it got to do with then?

Timber products are in equilibrium and the only influencing factor to alter that state is humidity

 

[hermes]

For what it's worth, I did one like this last year. I battened under the stair string, battened down the wall on the left and on the panel on the right, and then 2" x 1" battens down to the floor on each side of where I wanted the opening to be. I fixed these 2 battens to the floor (which was 19mm t&g) with corner braces and so there were only 2 screws going into the flooring...I would have done the same with a laminate floor, it's only to add a bit of stability really.

I cut 15mm Mdf to shape after I had run a saw down it to make grooves and make it look like T&G, and then glued and pinned it to the battens. As I had made the grooves I made it in 2 pieces and made the joint along a groove so it was invisible when assembled.

I made the doors a total of about 50mm wider than the opening, moulded the edges for decoration and fixed with flush hinges with magnetic catches at the top.

I had pre-primed it and it got caulked down the edges and then painted with emulsion when the wall was next painted and it looked great. No flexing or warping after 10 months.

The main difference from your drawings is that the top of my opening (and the top of the doors) followed the line of the stairs, but about 75mm beneath the string, as I thought it would give better access, and I think it looked better like this than if the opening had been square. As the doors were surface fixed rather than flush (ie. sitting inside the frame) there was no issue with the sloping top of the LH door binding on the frame as it opened.

 

[sadams]

just wanted so say thanks for all the advice...I know it was a while ago now but (apart from hanging the door which is on my todo list) its now finished and being used...all painted and blends in really well with the rest of the hall way so thanks to everyone who gave me advice!