The Impact Of The Grit Sequence During Floor Sanding

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The Impact Of The Grit Sequence During Floor Sanding

The Impact Of The Grit Sequence During Floor Sanding

During the floor restoration project, the surface is sanded over multiple times. For property owners having their floors sanded for the first time, there is usually a misconception that all it takes is one girt of sandpaper to leave the surface all flat, clean and smooth. However, it is a process. There is one core aspect: the grit sequence. Basically, it starts with the more abrasive grits, working up to the finer grits. At the start, the goal is to remove the finish that is on the surface, while as one goes to the successively finer grits, focus shifts to removing the sander marks and smoothening the area. Picking the wrong grit sequence can result in time and resource wastage. It is also vital to obtain a smooth transition from one grit to another, otherwise the sander ends up leaving behind grit lines that are unsightly and will affect the final treatment process. This is one area where DIYers make mistakes, complicating the floor restoration project, hence the insistence on one relying on professional floor sanding services. Depending on the condition of the floor, it can take a number of different grits to get the desired final smooth result. However, when working with the right sanding sequence, the professionals minimise the amount of time and resources that will be needed, with each pass being effectively done. The selection of the sanding sequence comes down to factors such as the current finish that it has been treated with, where there are wood stains or paint that are on the surface, the age of the wood, all through to the species itself. There are also situations where the sanding is carried out in the middle of the finishing process, such as in between consecutive coats that have been applied. This one is more delicate since the focus is on simply smoothening the previous coat to prepare it for the subsequent layer that is to follow- not removing it in its entirety. Hence the grit that is employed for the task becomes a very vital selection. The various grits can be categorised as:



Here, you have grits like 12, 16, 20 and 24. The 12 grit is the coarsest, and is typically used when sanding the hardwood floors that have heavy adhesives, or a situation where the surface has been treated with several paint coats. When dealing with floors like maple, those that have shellac finishes, or here there is a single layer of paint, the floor sanding can start with the 16 grit. Grit 20 is used when the focus shifts to flattening the floor, as it is effective enough to remove plenty of the wood stock even for those situations where the wood species is very hard. The 24 git then comes in to deal with sander flaws such as any swirl marks that may have been formed. It is also used when the existing finish has worn down all through to the bare wood in sections of the floor. In case the surface hasn’t been sanded for over 3 decades, or where it has a coat of finish that is relatively heavy, the sanding can start at the 24 grit.


  • Coarse


Grits 30, 36 and 40 come in here. When dealing with the newly installed floors, the sanding can start at grit 36. This also applies to the cases of over-wood, since the grit is sufficient for removing it and making the floor boards flat.


  • Medium


At this stage, the grits are 50 and 60. There, the grits work to remove the scratches that result from the previous stages. These are not used as starting grits.


  • Fine


This starts out at grit 80 to 100. At grit 80, most standard floors are sanded up to this point, as it will have removed the scratches from the sandpaper with 60 grit. The 100 grit- is usually used for the final grit floor sanding for species like birch and maple, and similar hardwoods, plus the surfaces that are to be stained.  


  • Extra fine


At this point, the grit levels are the likes of 120 and 150. The sandpaper is extremely fine. These are used to remove any scratches from the lower grits if necessary. 

Mistakes Made During Floor Sanding With Regards To The Grit Levels Used

For starters, there is simply following the wrong grit sequence. Starting with high grits then the low, inter-changing in the middle of the process- they can make the task take longer than is required, and cause wastage of the sandpaper being used. Then there are those cases where one starts out with grits that are too fine- perhaps due to the fear of sanding out too much into the wood than is required. Here, the floor refinishing will not be successful, since there will be sections of the surface that will still have coats of the old treatment, preventing proper bonding with the new coats that are to be applied. There are also those cases of excessive sanding, in which situation the DIYer eats too much into the wood than is required. This weakens the structure, and reduces the lifespan of the installation. These blunders can be avoided by enlisting the services of a floor sanding professional, who will ensure the right measures are used for the task.

Get In Touch With The Professionals

The floor sanding itself is a labour intensive job, and with so many balls to juggle to enable you to have satisfactory results, you don’t want to take it on as a DIY project. Lugging around heavy machinery, ensuring that it is properly tuned, issues such as the speed with which the passes will be made on the floor surface, how the dust that is generated during the sanding will be handled- these can take a toll. Even an aspect such as the direction to follow while sanding with regards to the grain pattern also weighs in. Then there is the sheer amount of time that will be required, especially when working with low capacity machinery. Leave the task to the experts, who come with industrial-grade floor sanding machines, plus a wealth of experience to ensure that your particular needs are satisfactorily met.

The Impact Of The Grit Sequence During Floor Sanding

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