Filling and Sanding Inside the Tiny House

Marc Bilodeau/ Building, Tiny House

What a big difference a little filling and sanding make. I always thought the purpose of sanding is to remove any splintering on rough wood. However, it is much more than that. With a lot of the tiny house interior complete, sanding makes a big difference in both smoothness and appearance.

[Photo Album]

So why go through the extra effort? There is about 4 hours of work dedicated to filling and sanding at the time of this writing. Also, I estimate another 4 or 6 hours to finish. That’s a lot of time for an 8′ x 20′ (~ 2.4m x ~ 6.1m) tiny house.

However, sanding is only one step. Every nail hole, window and door corner, and screw head in the walls have been filled with wood filler.

Wood Filler

Filling isn’t really necessary. Its purpose is to fill in the holes and corners for a nice finish, and the surface looks like one contiguous piece. Also, it repairs those nicks in the wood’s surface. Once the filler is dry, use sandpaper to sand away the excess material.

Before and after example of sanding and filling
Left, before sanding. Middle, after sanding. Right, a cabinet door under the stairs. 

I highly recommend taking the extra time to fill and sand. It looks amazing. However, there are different types of filler for different materials. If the surface is going to be stained, a solvent-based wood filler may be more appropriate. Some fillers contain actual wood material, so they will stain like real wood. Others aren’t stainable or paintable but come in a variety of tints. The wood filler in this tiny house is paintable. Also, it works on exterior surfaces.

There is a second type of filler above the shower since the surface material is different. For this job, bright white caulking takes care of those nail holes and seals the edging of the shower. The caulking also dries white like the surface. This is important since that surface will likely not be painted.


Sanding seems straightforward. You take a piece of sandpaper and rub it across a piece of wood until it looks and feels smooth. However, it’s a little more involved. Sandpaper contains little sharp edges that scrape away wood or metal. Yes, metal.

Sandpaper is measured by grit. The higher the grit, the more sharp edges per square inch of sandpaper. Different grits are for different jobs. For example, one should use a coarser sandpaper between 40 to 60-grit for heavy sanding. 80 to 120-grit sandpaper is good for smoothing surfaces and removing small imperfections. Above 120-grit is to sand surfaces smooth. Surprisingly, there are grits over 1000.

Some of the different sandpapers used in the tiny house
Sandpaper comes in all shapes, grits, and sizes

With so many grits, it was a little overwhelming at first. However, my desire to simplify everything helps narrow the choices. The 40 and 60-grit is for the rougher wood, and the 120 and 150-grit is for sanding all finish surfaces. The higher grits also take care of smoothing the surfaces with any excess filling.

tiny house bathroom shelves
This is just a taste of the results from filling and sanding

An electric palm sander saves a lot of time and elbow grease. Most of the work throughout the tiny house uses one. Although, some of those tight corners require sanding by hand. This is especially true on the cabinets over the sink and above the cooking station.


Take the time to do some filling and sanding. Although, finish work takes time and progress seems to slow, the end results are well worth the effort. Determine which filling is best for the surface, and sand it smooth with the proper grit of sandpaper.