A general rule of thumb for your baseboards is the 7 percent rule — they should equal 7 percent of the overall height of your room. So, if you have 8-foot ceilings, your baseboards will look best at around 7 inches high.
Here is a great rule of thumb: A standard 8-foot wall typically has a baseboard 3 to 5 inches tall, while a 10-foot ceiling calls for 5 to 7 inches. As a designer, I love adding height for drama. And the taller baseboards create a modern yet elegant finished look.
When choosing the baseboards for your home, you must stick to the measurement recommendations for the height of your ceiling. Overly tall baseboards can shorten a room while short baseboards can get lost in a room with tall ceilings. If a replacement is not an option, allow your creativity to flow by adding layers.
If you plan to install baseboard moulding before adding carpet, it needs to be installed 1 inch above floor level to allow room for both pad and carpet. If adding baseboards after carpet is laid, it should be installed at the same height as without carpet.
The standard size of a baseboard generally varies in relation to the wall's height. Most baseboards are about 1/2- to 1-inch thick and anywhere from 3- to 8-inches in height. The measurement can also vary depending on whether or not crown molding is installed.
A baseboard height that's approximately 7% of the wall height provides for a solid and definable base without being too big. The overall proportion of baseboard to wall height will be comfortable and pleasing. So in a room with a 9 foot high ceiling, a baseboard that's about 8 inches tall works.
What is the most popular baseboard trim? Three inch rounded or stepped baseboard is the most common type of baseboard. This type gives a little bit of design to the baseboard as well as detail without going overboard and making it overwhelming.
The Standard
If you are just replacing the baseboards without flooring in place, then most contractors will ask you to give them between ⅜ and ½ inch of room between the subfloor and the baseboards. This will allow them the room they need to tuck your flooring underneath the baseboards.
Baseboards should only touch the floor if you have no plans to carpet your floors and if you've already finished installing your other flooring. If you have yet to install the rest of your floor, carpet or otherwise, you'll need to take into account the height of the installed flooring.
If you plan on installing carpet, your baseboards should be about 1 inch off the floor. This will give you enough room for the padding and the carpeting. If you are leaving the floors uncarpeted, you should not have any gaps. At most, the gap should be around the width of a quarter to prevent heavy drafts.
For an 8 foot ceiling height the recommended crown size is 2-1/2″ to 6″ tall with no picture mold. Use the square footage and level of formality of the room to choose an appropriate crown size and style in that range.
One possibility to trick the eye and visually increase the height of your baseboard mouldings is to “re-create” them with a faux-finish. Decide the height you want the finished baseboard to be, mark it and then install a thin, simple moulding at this height line, all around the room, above the existing baseboards.
Select baseboard that is tall enough to "be a noticeable accent without overpowering," according to the website One Project Closer. One rule of thumb is to use baseboard that is 5-1/4 inches tall for a room that is 8 feet tall. Use taller baseboard in taller rooms.
Base Molding
The standard method of installation is to install two nails over each wall stud. The top nail should hit the stud and the bottom nail should either hit the stud or the floor plate, which is 1-1/2 inches higher than the subfloor.
Caulk at the bottom of the baseboard reduces the risk of this happening. Gaps and cracks around baseboards give insects an easy way into your walls where they can build nests and eat away at the structure of your home unseen. Caulk on both the top and bottom edge of the baseboards closes the gaps to keep the bugs out.
Baseboards are usually installed before flooring with a reservation gap left at the bottom of the baseboards for the flooring to be slid underneath. The gap left under baseboards for flooring is dependent on the width of the flooring being installed.
The recommended expansion gap is a minimum of ¼ inch. Expert installers say that the larger the space, the larger the expansion gap should be, as the floor needs more space to expand and contract with temperature.
Generally, the installation of carpet or baseboard is easier for whoever installs first. Some professionals may have a strong preference, but ultimately baseboards can be installed before or after carpet.
Even though simple baseboards are a hallmark of modern design, there's no reason that you can't incorporate a more traditional baseboard style into your modern home.
Hardwoods. Hardwoods like oak and maple are an excellent choice of baseboard materials if seeking wood baseboards that can be stained. Hardwoods take stain and varnish well but are significantly more expensive than jointed pine and MDF. Hardwoods are popular as baseboards because of their durability.
For classic or traditional interiors, using a white or off-white paint can really play up the trim and bring out its historical or intricate qualities. And many design experts consider white the perfect color for any trim, regardless of interior style or wall color.
A general rule followed by most installers is to keep the baseboard thickness about one-eighth inch thinner than door and window casings. This creates a slight relief at the base of the door frame and also allows for slight imperfections in the way the door is hung.
Standard thickness for exterior trim is almost always 3/4 inch, but when using rough saw lumber, such as cedar, the width may vary. Fascia board -- the board that runs horizontally around the perimeter of the roof -- has no standard rule for sizing.