PLASTERING FLOAT
Plastering floats are for flattening, keying and finishing plaster or render without dragging the surface to bits. Pick the face to match the coat.
When the wall is pulling in and you need to close it up, level high spots or bring aggregate through on render, this is the bit of kit you reach for. Plaster floats, sponge floats, polyurethane floats and devil floats all do different jobs, so match the float to the finish, not just the price. If you are building out your kit, start with the right Trowels and get the float that suits the coat you are working.
What Are Plastering Floats Used For?
- Flattening fresh backing plaster on walls and ceilings helps take out ridges and hollows before final trowelling, which saves you fighting the surface later.
- Working a sponge float over finishing plaster or render lifts a bit of moisture back to the face and helps tidy up marks, edges and uneven patches.
- Closing up render coats with polyurethane floats or plastic plastering floats gives you a more even face and helps consolidate the material without dragging out the mix.
- Keying scratch coats with devil floats leaves the surface ready for the next coat to bite properly, which matters on rendering jobs where bond is everything.
- Cleaning up reveals, patch repairs and small boarded areas is easier with hand floats for plastering when a full trowel pass is awkward or overkill.
Choosing the Right Plastering Float
Sorting the right plastering float is simple: match the face material to the coat and the finish you are trying to leave.
1. Sponge vs Plastic vs Polyurethane
If you need to bring moisture back up, blend edges or tidy a rubbed finish, use a sponge float. If you are closing up render or floating out a coat without too much drag, plastic plastering floats and polyurethane floats are usually the better shout.
2. Fine Finish vs Keying Up
Do not use the same float for every stage. A smooth plaster smoothing float is for levelling and finishing work, but if you need to scratch or key a coat for the next pass, go straight for a devil float.
3. Size and Handle Comfort
If you are on bigger wall areas all day, a full-size float covers ground quicker. For reveals, patching and tight spaces, a smaller hand float is easier to control and less likely to mark the work.
4. Buy for the Material You Actually Use
If most of your work is internal skim and patching, a sponge float and a standard plaster float will cover most jobs. If you do more outside rendering, make sure you have render floats that can cope with rougher mixes and bigger aggregate.
Who Uses These on Site?
- Plasterers use plastering floats every day for flattening backing coats, sponging up tight areas and getting a consistent finish before the final polish.
- Renderers swear by render floats and devil floats because they help close the face, level the coat and leave the right key between passes.
- Brickies and general builders keep plaster floats handy for patching reveals, tidying repaired areas and sorting small render sections without overworking them.
- Dry liners and snag teams reach for them on patch jobs around boards, beads and openings, especially when paired with Dry Lining Tools for fast touch-ins.
The Basics: Understanding Plastering Floats
Plastering floats all do the same core job of working the face of the material, but the float surface changes how aggressive or smooth that action is. That is what decides whether you flatten, close, key or tidy the coat.
1. Smooth Floats
These are for flattening and evening out plaster or render without cutting deep into the surface. They help take out bumps and leave the coat ready for the next stage.
2. Sponge Floats
A sponge face holds water and lightly opens the surface back up. That is useful when you need to blend trowel lines, rub up render or work back over an area that is starting to pick up.
3. Devil Floats
These have nails or points that rough up the coat to form a key. On rendering work, that bite is what helps the next layer hold properly instead of sitting on a slick face.
Plastering Float Accessories and Kit That Save Time
The float matters, but a few supporting bits stop the usual mess, wasted material and awkward rework on plastering jobs.
1. Mixing Buckets and Paddle Mixers
A float cannot rescue a bad mix. Use proper buckets and Paddle Mixers so your plaster or render is consistent from the start, not lumpy and fighting you on the wall.
2. Trowels
You will nearly always use a float alongside Trowels. The float levels and works the face, then the trowel closes it up and finishes it properly.
3. Trade Specific Plastering Hand Tools
Keep the rest of your setup right with Plasterers & Brickies Tools for hawks, edging tools and other bits that stop you making do with the wrong kit halfway through a set.
4. Brand Matched Replacements
If you already rate a certain handle shape or float feel, sticking with ranges like OX Plastering Tools makes it easier to replace worn kit without changing how you work.
Choose the Right Plastering Float for the Job
Pick the float by stage of work and surface finish, not just by what is nearest in the van.
| Your Job | Category or Type | Key Features |
|---|---|---|
| Flattening backing plaster before final finishing | Standard plaster float | Smooth face, good coverage, controlled levelling without tearing the coat |
| Rubbing up render and blending marks | Sponge float | Absorbs water, reworks the surface, helps tidy edges and light imperfections |
| Closing up sand and cement or monocouche style render | Polyurethane or plastic float | Firm face, low drag, handles rougher mixes better than a soft sponge |
| Preparing a scratch coat for the next coat | Devil float | Spiked face, cuts a solid key, improves bond between render coats |
| Patching reveals, corners and smaller repaired areas | Small hand float | Better control in tight spots, easier to work without marking finished areas |
Common Buying and Usage Mistakes
- Using a sponge float for every stage is a common mistake. It is handy for rubbing up and blending, but if you try to flatten whole coats with it, you can end up dragging the surface and losing shape.
- Buying one float and expecting it to cover skim, backing plaster and render usually ends in compromise. Different coat types need different float faces, so build a small working set instead of making one tool do everything badly.
- Leaving float work too late makes the job harder than it needs to be. Once the material has gone too far, you will fight the face, tear it up or leave marks that should have been dealt with earlier.
- Choosing the cheapest handle without thinking about grip is false economy. If it twists in a wet hand or digs into your palm all day, your control drops off and the finish usually shows it.
- Not cleaning floats properly after use shortens their life fast. Dried plaster on the face leaves ridges and hard spots, which then mark the next coat and cost you time rubbing it back out.
Sponge Floats vs Plastic Floats vs Polyurethane Floats
Sponge Floats
Best when you need to rub up a surface, blend marks or bring a bit of moisture back to the face. They are useful for finishing touches, but they are not the best choice for flattening larger coats or keying between layers.
Plastic Floats
A good all-round option for closing and smoothing render without too much drag. They clean up easily and suit trades who want a firmer feel on the face than sponge gives.
Polyurethane Floats
Usually the pick for rougher rendering work where you want a solid float that can cope with heavier mixes and leave an even face. They tend to hold up well, but they are less forgiving than sponge on delicate touch-up work.
Devil Floats
These are not finishing floats at all. They are for scratching and keying coats, so buy one if you do proper render build-ups, not if you are only doing skim repairs and internal patching.
Maintenance and Care
Clean Straight After Use
Do not leave plaster or render to set on the face. Wash floats off as soon as the job is done so dried build-up does not scratch or mark the next coat.
Check the Face for Damage
A nicked plastic edge or torn sponge will show up on the wall. If the face is uneven, replace it before it starts costing you time on snagging and rubbing back.
Store Flat and Dry
Do not chuck floats under heavy gear in the van. Keeping them flat and dry helps stop warped faces, crushed sponge and handles working loose.
Watch the Handle Fixing
If the handle starts moving, sort it early. A loose handle kills control and leaves you fighting the tool, especially on longer wall runs.
Replace Worn Specialty Floats
Sponge floats lose bite and devil floats lose effectiveness once worn down or clogged up. When they stop doing their specific job properly, bin them and carry on with a fresh one.
Why Shop for Plastering Floats at ITS?
Whether you need standard plaster floats, plastering sponge floats, render floats or devil floats, we stock the range that actually gets used on site. It is all in our own warehouse and ready for next day delivery, so you can replace worn kit or build out your float setup without holding the job up.
Plastering Float FAQs
What is a plastering float used for?
A plastering float is used to level, flatten, close up or texture plaster and render depending on the face material. In simple terms, it helps you get the coat into shape before final finishing, and some types like sponge floats or devil floats are for specific stages rather than general use.
What is the difference between a plastering float and a plastering trowel?
A float works the surface more broadly and is often used for flattening, rubbing up or keying. A plastering trowel is for laying on, refining and finishing the surface. Most proper plastering jobs use both, not one or the other, because they do different parts of the process.
Should I use a sponge, plastic or polyurethane float?
Use a sponge float when you need to blend, rub up or bring moisture back to the face. Use a plastic or polyurethane float when you want to close up render or smooth a coat with a firmer face and less drag. If you mainly do render, plastic or polyurethane usually earns its keep quicker.
When should I use a float while plastering?
Use the float once the material has firmed up enough to work without collapsing, but not so late that it tears or drags. The exact timing depends on the mix, the background and site temperature, but the rule is simple: if the coat is still too wet, leave it; if it has gone too hard, you are already making life difficult.
Can plastering floats also be used on render?
Yes, plenty of plaster floats are used on render, but you need the right type. Sponge floats, plastic plastering floats, polyurethane floats and devil floats all have their place on rendering work, from rubbing up the face to keying a base coat for the next layer.
Will a cheap float do the job, or is it false economy?
For the odd patch repair, a basic float can be enough. If you are using it day in, day out, cheap floats tend to wear unevenly, handles loosen off and the face can mark the work. That is when false economy starts costing you in finish quality and time.
