The kitchen unit is of course a box, in the industry it is called the carcass, and the decorative parts are the door fronts and the worktop section, but few people pay any real attention to the actual box itself. These can be made from many materials, but the most common is chipboard, and then there are still some who manufacture from plywood. Then there are a few differences in how the cupboards are actually assembled and held together.
What to look out for.
- Materials. Check what the carcass is made from and check the quality of the material and the finish.
- Assembly. Check how the carcass is put together, look where the panels join to see if the joints are tight and that the panels line up properly.
- Back Panel. See how rigid the back panel is and if it fully closes the back of the carcass. Some back panels are not full height.
- Service space. For ease of fitting it is good to have a space between the wall and the back panel which allows for pipes and electrical cables.
- Shelves. Look at the depth of shelves (front to back) and check that they maximise use of the available space, shelves often only use half the cupboard. Check for adjustment and the quality of the supports. With glass shelves ensure they are toughened glass and of adequate thickness.
- Fittings. Check hinges, drawer runners and internal fittings for smooth operation and strength.
This is a well tested and reliable material, but is available in different grades and with differing finishes on the surface. Generally kitchen carcasses are produced from Melemine faced chipboard which offers a fairly tough and easily cleaned surface, and has the advantage of availability in a range of colours and textures.
Boards come in varieties from 15mm up to 20mm in thickness, however a thicker board does not always mean a stronger board. Note too that the thicker boards offer less internal space, not hugely significant, but in a tight space it might be.
This is more of a factor in the strength of a board then the thickness alone. A high density board of 15mm thick can be stronger than a low density at 19mm thick. Unfortunately it is difficult to tell the density of a board unless you can see a cut edge.
The boards are cut in the factory into the required shapes and sizes for the component parts of the cupboard and this produces a raw unfinished edge. Where this is going to be exposed the board is edged, a process called edgebanding, to present a finished surface.
This is often a measure of the overall quality of the material and how much care is taken in the production process. If you have a close look at the edging you can spot if the material is evenly applied, or if it shows tiny chips or cuts which might indicate poor quality. Also patchy uneven colour on the edge could be an indication that the underlying chipboard is not a very high density.
Of course it is essential to take the cost of the kitchen units into consideration when making a judgement. The basic material quality is after all one of the factors which influences price, so don’t expect a budget priced range to compare to an expensive one! The quality of this basic material has a great effect on overall cost, but because the internals of the kitchen are not often examined closely, this is an area where the cost is only justified on close inspection.
Plywood is an excellent material for cabinet construction, but mainly due to its high cost, it is not used so frequently now. With a plywood carcass the finished surface is often left as a wood grain, but it could be painted or clear lacquered. Plywood also comes in differing grades, the best is widely recognised as Birch Plywood, and this is what most quality cabinets will be made from. Plywood will usually be 12mm to 15mm thick, so while thinner than some chipboards it is particularly strong. It does not require edging when cut and can be sanded to a smooth finish, but often a decorative edge is applied.
Kitchens fall into two distinct categories, flat-pack or self assembly, and rigid or pre-assembled. The difference of course is obvious, but if you could see the components in the factory it would be more difficult to distinguish which was which. All kitchen carcasses are made from pre cut panels, some are boxed in kit form and some are factory assembled.
Rigid kitchens tend to be regarded as superior, but that is not necessarily the case. If a flat-pack is correctly and carefully assembled it can offer just as strong and reliable a framework for your kitchen as a factory assembled.
The key is in how the panels are assembled. Today most flat pack carcass panels are joined using a cam and dowel system. This helps to minimise the risk of over-tightening screws which damages the chipboard, and makes assembly simple and quick. However it can in the case of some budget units, result in a carcass which wobbles slightly, and the alignment of the panels is controlled purely by the accuracy of the holes which have been pre-drilled at the factory. An experienced joiner will be able to sort out any such problems, but a well designed flat-pack properly assembled is usually stable and well aligned.
A quality system will use a combination of the mechanical (cam& dowel) fixing and traditional glued dowels. When carefully assembled this will provide a good stable carcass, and this is where the factory assembly usually wins. In the factory the correct amount of glue can be applied, the correct torque can be applied to fixings and the carcass can be assembled in a jig which ensures correct alignment of the panels. So the finished result depends on the quality of the assembly, so if you choose a flat-pack system either use a competent fitter or make sure you know what you are doing yourself.
When you are looking at kitchens, have a good look at the back in the cupboards, this can provide some clues about the quality of the overall carcass construction. The panels are usually either a melamine faced hardboard, or a melamine faced chipboard (normally thinner than the main carcass). Chipboard is more rigid, but hardboard is fine if it is properly fixed. Get down and push the back panel with your hand to test for movement. A little movement is not a problem, but the panel should not art company with the carcass sides.
You can expect a bit more movement in a bigger unit of 800mm or wider. These often have a jointed back panel and it is particularly important that jointed panels are well fixed.
Another thing to look for in the back panel is does it fully close the cupboard? Some carcasses have a back which is not full height, leaving a gap at the top which will allow dust, spiders etc into the cupboard space. A full height panel is much better. You might expect a half panel in a sink unit to accommodate plumbing, and of course, an appliance housing will not have a back at all.
It is much easier to fit a carcass which has a space between the back panel and the wall. A space of 40 to 50mm is ideal and this allows for pipes and electrical cables to be surface mounted on the wall behind the kitchen units. The gables of the units can be notched out to allow pipes and cables through.
Another reason for this gap is to allow the units to be scribed to the wall where the wall is not quite vertical. Even in new construction walls are often not exactly true, and the service gap allows for the gables od the carcass to be trimmed to ensure a precise fit.
Usually shelves will be of the same material as the carcass, unless they are glass. They can differ considerably in depth, with some kitchen manufacturers providing a shelf which is little more than half the carcass depth. There is the argument that this allows for taller items to be stored at the front, but the truth is that it cuts costs. Do think about the storage you require and how the shelf size might affect you. It has no bearing on the quality or strength of construction, but could have an influence on practicality.
Look at the shelf supports. Mostly these are a plastic or plastic and metal plug, so just ensure they are strong and positioned where they will offer good support to the shelf. Look for some adjustment too, which will allow you to change the height of the shelf to suit different contents.
Pay particular attention to wall unit shelves, and check the internal size of the wall cupboards. There are still some on the market which are not deep enough to store a dinner plate. Look for the internal depth to be very close to 300mm.
If you are considering glass shelves they need to be toughened glass for safety, and look for a thickness of around 4mm.
Look for hinges and drawer runners which are all steel and avoid a mixture of steel and plastic. Plastic components will wear more quickly, resulting in doors which do not hang properly and drawers which are not smooth. Soft close options are nice and offer a quality feel to your kitchen but they are not essential, so don’t be put off if everything else checks out, but soft close hinges are missing. They can be usually added as a low cost extra.
If there are internal baskets, pull-out systems or other wire-work accessories, ensure that they run smoothly, and like the hinges, look for all metal construction, particularly the mechanism.