A neatly applied bead of caulk can completely transform a decorating job. It smooths the joins between walls, ceilings, and woodwork, seals edges, and instantly makes the whole space look more polished. With the right product, a few tools, and some simple techniques, you can master applying decorators caulk as a DIYer.
In this guide, we’ll focus on what decorators caulk is, why it’s worth using, where to apply it, and share simple, step-by-step instructions for how to use decorators caulk in the home.
Done well, caulk doesn’t just look neat - it also seals out draughts, prevents moisture damage, and reduces the risk of future cracks.
What is decorators caulk?
Decorators caulk, also known as decorators' filler, is a flexible, water-based acrylic filler designed to fill fine cracks and low-movement gaps before you paint or paper. It is the perfect companion for decorators or those taking on a renovation, to help prepare the interior areas in the home prior to decorating.
Why use it?
- Neater finishes: It hides hairline cracks and small gaps, so paint lines look sharp.
- Flexible and durable: Formulated for joints where slight movement is likely, such as walls and ceiling lines, skirting, and architraves. When properly applied it’s designed to last for years.
- Decorator-friendly: Water-based, easy to smooth, and paintable once dry.
Where to use it?
- Decorators filler is a versatile product that can be used in most areas within the home, including:
- Plaster and plasterboard
- Window and door frames
- Skirting boards
- Coving
- Other internal fixtures where joint movement is low
Although most decorators caulks are intended for interior use only, EVO-STIK Decorators Flexible Filler may be used externally provided it is allowed to set in warm, dry conditions with no chance of rain during the first 24 hours after application.
Recommended product: EVO-STIK’s Flexible Decorators Filler.
Top tips when applying decorators caulk
Discover our top tips to keep in mind, to ensure you apply decorators filler accurately for a professional-looking finish.
- Right product, right place: Use decorators caulk for paintable, indoor gaps. Do not use to seal sanitary areas such as in bathrooms and around sinks.
- Mind the weather (exterior use): Only use outside if you’re guaranteed warm, dry weather - no rain for the first day. Then paint to prolong the life of the product.
- Avoid over-filling: Deep gaps may need two lighter passes rather than one heavy bead to reduce shrinkage lines.
Step-by-step: How to apply decorators caulk
Before getting into the step-by-step instructions, its important to know the tools you may need ready at your disposal when applying decorators filler.
What you’ll need
- EVO-STIK Flexible Decorators Filler
- Caulking gun
- Sharp knife
- Masking tape (optional, for super-clean lines)
- Smoothing tool
- A bowl of warm soapy water and a clean cloth
1. Prepare the surface
Although it may seem counterproductive, the first step is to widen and deepen the hairline crack before filling it. Using a sharp knife, carefully cut along the length of the crack to open it up. This helps to create space for a flexible filler, which is designed to move with your wall and prevent future cracking.
Once you've created the crack a few millimetres wider and deeper, remove dust, loose paint and grease. The area must be clean, dry and sound. On very porous surfaces (e.g., fresh plaster), lightly prime with diluted PVA (5:1, water:PVA) and allow to dry. This will help reduce suction and improve adhesion.
2. Apply masking tape
Apply masking tape along the edges of the area to define your bead and protect adjacent surfaces. This will be removed before the caulk skins over.
3. Cut and load the cartridge
Unscrew the nozzle and cut the dome of the cartridge cleanly, taking care not to damage the thread. Then, screw the nozzle back on.
Next, cut the nozzle at 45° to match the gap width and load into the gun.
Tip: When cutting the nozzle, start small - you can always make it bigger, if required.
4. Apply a steady bead
Start at one end, keep the nozzle moving at a steady pace, and maintain even pressure so the decorators caulk makes contact with both sides of the gap. This helps to ensure an even spread and avoid any gaps or lumps during application. Then, release the plunger at the end of each run to stop the flow of filler.
Tip: It is recommended to work in manageable sections to ensure application is as smooth as possible.
5. Smooth the caulk
Immediately smooth the caulk with a smoothing tool to create a seamless application. Wipe away excess product with a clean cloth dampened in warm, soapy water before it fully cures.
If masking tape has been applied, carefully remove it before the surface skins - typically within 15–60 minutes, depending on temperature, depth, and humidity.
6. Let it dry, then paint
Once the filler has dried, it's now possible to paint the area, if required:
- Thin fills (<1 mm): You can often paint in as little as ~30 minutes in good drying conditions.
- Deeper gaps (≥5 mm): Allow at least 24 hours before painting so you don’t risk crazing or cracking the paint film as the caulk shrinks while drying. Always ensure it’s fully dry before painting.
Round-up
You're done! Applying decorators caulk can be super simple when you have the right tools and guidance to assist you.
With EVO-STIK Flexible Decorators Filler, you’ll get a flexible, paintable finish that tidies edges and hides hairline cracks - just prep well, apply a steady bead, smooth immediately, and wait the right amount of time before painting.
For full technical and safety details (including SDS), check the product page before you start.
