Hz RENOVARE – RENEWING EXISTING ACOUSTIC CEILINGS
Hz Renovare is our solution for acoustic ceilings that work but look worn. Hz Acoustic Plaster is sprayed straight onto the existing ceiling, which is left even and refreshed. No stripping out, no construction waste, and the acoustics are preserved.
We renovate two types of ceiling: wood wool ceilings that have darkened, and acoustic plaster ceilings from other manufacturers.
Before
After
TWO CASES
The plaster type is chosen to suit the existing ceiling. Both solutions are carried out by an Hz Partner.
The ceiling is dark and uneven after many years and may start to shed. Hz Acoustic Plaster 09 is sprayed straight onto it, and the ceiling is white and even again – or a completely new color.
SUBSTRATE
Wood wool
RESULT
Textured surface
PRICE
From 26 EUR/m²
Stains, cracks, yellowed patches or damage after an installation. Hz Acoustic Plaster C is designed to go on over the existing surface, so the ceiling keeps its appearance.
SUBSTRATE
Existing acoustic plaster
RESULT
Fine texture
PRICE
On assessment
WOOD WOOL CEILINGS
Many buildings have wood wool ceilings that still absorb sound but have darkened, stained or gone uneven over the years. Instead of taking the ceiling down and putting up a new one, it is upgraded in place.
Hz Acoustic Plaster 09 is made with recycled textile waste and sprayed on in two to three coats. The surface is left even and refreshed, while the ceiling’s architectural character is preserved.
Why wood wool must not be painted. Wood wool is chosen for its open, sound-absorbing structure. Paint closes the pores, and repeated coats cut sound absorption. The original acoustics cannot be restored once the pores are closed. Hz Acoustic Plaster 09 is acoustically transparent and does not seal the surface.
Joints and junctions. The joints between the boards are sealed with an overpaintable, UV-resistant sealant.
A new color. The ceiling can also change color, to black for instance. We can make digital visualizations, so the result can be judged before work starts.
ACOUSTIC PLASTER CEILINGS FROM OTHER MANUFACTURERS
Many acoustic plaster ceilings cannot be patch-repaired without visible traces. Once a ceiling has picked up stains, water damage, cracks or holes from new installations, it often ends up being replaced.
It does not have to be. We regularly refresh ceilings finished with acoustic plaster from other manufacturers. For those we use Hz Acoustic Plaster C, a mineral-based plaster with a fine texture, developed to go on over the existing surface.
After the renovation the ceiling stands as an Hz ceiling and can be repaired and maintained with a light sanding from then on.
Before
After
ACOUSTICS
What matters most in an acoustic ceiling is that it absorbs sound. Hz Renovare has therefore been measured before and after on a wood wool ceiling.
With Hz Acoustic Plaster 09 the measurements show unchanged sound absorption, and slightly improved across parts of the frequency range. The improvement covers most of the speech range (approx. 250–2000 Hz) and is greatest around 500 Hz.
Ordinary paint does the opposite: it lays a film over the surface and reduces sound absorption.
A wood wool ceiling with Hz Acoustic Plaster 09 compared with untreated wood wool. Positive values indicate improved sound absorption.
The speech range, approx. 250–2000 Hz
PROCESS
Each renovation is planned around the individual ceiling. The quantity of material and the build-up depend on the ceiling’s condition and absorbency, surface wear, any change of color and the finish required.
An Hz Partner assesses the existing ceiling and decides whether it is suitable for Hz Renovare, and which plaster type to use.
The ceiling is lightly cleaned and minor damage repaired. Joints and wall junctions are worked as needed.
Hz Acoustic Plaster is sprayed on in two to three coats. No ceiling comes down, so no demolition waste arises.
The plaster dries in about 24 hours depending on temperature and ventilation. The ceiling is then finished and can be maintained as needed.
BEFORE AND AFTER
Ceilings we have renewed with Hz Renovare. Drag the handle to compare.
Before
After
Before
After
INDICATIVE PRICES
The price depends on the ceiling’s condition and size, and on any change of color. The final price is stated in the quote from your Hz Partner.
From 26 EUR/m² excl. VAT
Includes light cleaning and Hz Acoustic Plaster 09 in 2–3 coats. Joint sealing and a color change are priced separately.
Quoted after assessment
The price depends on the existing surface and the extent of the damage. An Hz Partner assesses the ceiling first.
FAQ
Do you have a question that is not answered below?
See our general FAQ or contact us directly.
Most of them. The ceiling must be firmly fixed and stable. Loose boards, water damage or heavy decay must be repaired first. An Hz Partner assesses the ceiling beforehand, and the assessment also sets the quantity of material.
No. Hz Acoustic Plaster 09 is acoustically transparent and does not close the wood wool’s pores. Measurements before and after show unchanged sound absorption, slightly improved across parts of the frequency range. Paint does the opposite.
Yes, the surface can be renewed. But the absorption the paint has taken will not come back, because the pores are closed. Hz Acoustic Plaster 09 preserves the acoustics the ceiling has today.
Yes. We regularly refresh ceilings finished with acoustic plaster from other manufacturers. For those we use Hz Acoustic Plaster C, which goes on over the existing surface, so the ceiling keeps its appearance.
The plaster is applied in two to three coats and dries in about 24 hours depending on temperature and ventilation. The total time depends on the ceiling’s size and condition.
TECHNICAL DOCUMENTATION
Download product data sheets, ERFA sheets and EPD documentation for products related to Hz Renovare below.
EPD DOCUMENTATION
Send us a couple of photos of the ceiling and we will assess whether it is suitable for Hz Renovare. Or find an approved Hz Partner in your area.
