How to Build Floating Shelves in an Alcove

The Problem

After a recent refurb of our living room we were left with two bare looking alcoves either side of the chimney breast. We decided they needed some shelves and we really wanted floating shelves. Floating shelves look as they are floating without supporting brackets and therefore look much neater. However, trying to find ready-made shelves that fit your particular alcove perfectly is nigh on impossible unless you are very lucky. Apart from the length and depth being exactly what you want, your problems are likely to be compounded by the fact that your alcoves will likely not be square. We live in an old Edwardian terrace and there isn’t a right angle in the place! However, you can build DIY floating shelves for under £10 each and it is actually much easier than you may think, easily within the capabilities of most people who can use a saw and a tape measure.

The Naked Alcove

Commercial custom built floating shelves are an option but are very expensive, £50 each and more, and even these will not allow for the sides of the alcove not being square to the back wall or parallel to each other. Most of these floating shelves rely on a bracket that screws into the back wall only and the shelves slide onto rods or similar to hide the bracket. This doesn’t sound like a very sturdy option to me and if your back wall is not perfectly flat your floating shelves won’t be either. Adding to that, our alcoves were wider at the back than the front making it pretty much impossible to fit a ready-made shelf that wouldn’t leave gaps.

The Solution

I decided the only option was to build some floating shelves from scratch. The first thing to do is decide on the number of shelves and the spacing. We went for four floating shelves each side with the bottom shelf almost the full depth of the alcove and the other shelves somewhat shallower. We also decided to have a larger gap between the bottom shelf and number two shelf, more space for a lamp etc, all down personal preference here really.

Screw and Wallplug Size

Next you need to choose your materials and this will depend on how thick you want your shelves to be. We decided 45-50mm thick shelves gave the look we wanted so I purchased some 34mm x 34mm planed batten and some sheets of 6mm MDF board. This should give shelves around 46mm thick (34mm plus 2 x 6mm). You will also need screws and wall plugs. I used size 8 x 65mm screws with the appropriate sized wall plugs. Remember the wall plugs only need to be long enough for the amount of screw that will protrude through your batten.

Getting the Job Done

Once you have decided exactly where you want your shelves and the size, you need to start cutting the batten to size. This is where you start to allow for variations in your alcove dimensions, cutting the size of the battens to the size of the alcove at the individual shelf position. For each shelf you obviously need two long strips, front and back, and two short for the sides. I also decided to have one in the middle which doesn’t really give much structural support to the shelf but provides a further point of fixing for the MDF shelf surface.

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Then you start by screwing the first batten to the back wall of the alcove, making sure it is perfectly level. For additional support you can use Pink Grip, No More Nails or similar. Then fix the sides, again ensuring they are level, and finally attach the front strip. You should pre drill the all the holes in the batten to avoid splitting and countersink them, especially the front batten as you are going to need to hide these screws. If you decide to add the middle support you can fix it at the back by inserted a screw at 45 degrees. As well as using adhesive to help the screws stick the battens to the wall, I used some PVA wood glue at the joints too.

Frames Taking Shape

Then just repeat this for your other shelves, not forgetting to adjust the batten size if you’ve decided your bottom shelf is going to be deeper.
Once you have finished the frames you will need to cut the MDF to make the surface, top and bottom. This again is where you can adapt to any unevenness in your alcove so you will need to measure each shelf carefully. This is where an adjustable square or carpenter’s sliding bevel will come in very handy as you need to measure the angles at the sides and back relative to the front batten. Starting with the top of your first shelf, measure the angles and the lengths of each side carefully. Using the machined edge of your MDF sheet as the front (this edge is going to be flush with your front batten), draw out the shape of your first shelf. Once you are sure it’s OK, cut it out, preferably using a jig saw or fine tooth circular saw. A slight shortcut here is that you can use the top sheet for each shelf as a template for the bottom, it’s unlikely your walls change that much over an inch or two. Don’t worry if you mess one or two up, MDF is cheap and it’s worth persevering to get a nice fit.

Once you have cut out the shelf surface you need to attach it to your battens. Now you don’t really want to be testing all your battens with hammer and nails, although they should hold up! Glue and clamping would do but I opted to buy a cheap nail gun, so glued and nailed with the gun. At £50 it didn’t add much to the overall project cost and now I have a free nail gun to use elsewhere!

Fill the Gaps

Clear the Excess

No matter how good your measuring you will have some gaps. These can easily be filled with decorator’s caulk. At around £1 a tube this is about the best value and most useful product ever available in a DIY store! At the front of the shelves you will also have some countersunk screws to hide with filler. For the front you could buy pine strips or similar but you would have to plan ahead and build your shelves to the thickness available unless you have a table saw or other means of cutting to the exact thickness of the shelf neatly. I chose to simply fill any small gaps and sand with a sanding machine until smooth. Just be careful sanding as the MDF is softer than the pine batten. A small sanding machine is easier to keep square on rather than doing it by hand. Once painted the join between the batten and MDF is virtually invisible.

Coat of Paint and Looking Good!

Once you’ve made sure all your nail heads are sunk and filled the front edge is filled and sanded smooth time to paint. I used a small roller with a couple of coats of good quality eggshell wood paint (B&Q Valspar paint is amazing by the way, fantastic coverage) which gave a nice, slightly textured finish. One thing to be aware of is that you will inevitably make some marks on your existing wall surface that will need touching up so make sure you have or can get the colour to touch up. Or, do what I didn’t do, plan ahead and build your shelves before you decorate!

The Result

So there you go. Each side probably took a weekend and overall cost, including the nail gun (I already had drills, sander etc) was less than £150, which I think is a bargain and I reckon they look OK. My wife likes them so that’s really all that matters.

Shout up if you have any questions, I’ll be glad to help if I can.