www.erfurt.com: Base surface inspection

Have questions about our products, their use, or any general questions about personal wall-design? You can find the answers to the most frequently asked questions (FAQs) right here. Just in case your question isn’t answered here, we’ll be glad to answer it by e-mail.

When must the various base surfaces be primed? And with what?: New plaster board surfaces must be primed with a solvent-free primer; Wood materials with a solvent-based primer. For all other absorbent base surfaces, see table (PDF).

The base surface must still be absorbent following priming.

Overview: Use of primer

Vorbehandlung.pdf

PDF file (36 KB)

Expert: ERFURT-Customer service
How do I obtain an evenly colored, and consistently absorbent base surface?: With a pigmented (white) primer.

Expert: ERFURT-Customer service
How can I inspect the base surface?: Inspect base surface for
Testing methods
Characteristics
Remedy
Alkalinity
Moisten with distilled water and place a strip of indicator paper on surface
If the pH level is greater than 8, the base surface is alkaline
Allow to dry
Efflorescence
Visible to naked eye
White salts are often visible
Determine cause and remove. Allow to dry using ventilation and heat. Brush away dried salt granules
Moisture
Visible to naked eye
Visibly moist surfaces or appearance of discolourations or water rings
Determine cause and remove. Allow to dry using ventilation and heat
Surface strength
Rub with hand
Scratch with a hard, sharp object
Dusty or chalky grit
Wash surfaces thoroughly with water
Fungal decay
Visible to naked eye
Dark fouling
Determine cause and remove, may need to remove and treat chemically
Cracks
Visible to naked eye
–
Depending on type of crack, spakle entire surface, then reinforce with crack covering or elastic fabric
Absorbency
Moisten with water
Too absorbent:
turns dark quickly
Not absorbent enough:
Water forms beads
Too absorbent:
apply primer
Not absorbent enough:
sand or apply primer
Sinter layers
Scratch or sand layer, then moisten with water
In case of dry base surface: glossy surface and minimal absorbency. After water test, scratched area turns darker
Sand away sinter layers

Expert: ERFURT-Customer service
Why is it necessary to inspect the base surface? And for what should it be inspect?: In order to wallpaper a surface, the surface must be appropriate for papering. Otherwise, there may be difficulties with adhesion. The base surface must be dry, clean, firm, absorbent and smooth. Fleece wallpapers (that are not painted over) require a base surface that has a consistent colour.

Expert: ERFURT-Customer service

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Inspect base surface for	Testing methods	Characteristics	Remedy
Alkalinity	Moisten with distilled water and place a strip of indicator paper on surface	If the pH level is greater than 8, the base surface is alkaline	Allow to dry
Efflorescence	Visible to naked eye	White salts are often visible	Determine cause and remove. Allow to dry using ventilation and heat. Brush away dried salt granules
Moisture	Visible to naked eye	Visibly moist surfaces or appearance of discolourations or water rings	Determine cause and remove. Allow to dry using ventilation and heat
Surface strength	Rub with hand Scratch with a hard, sharp object	Dusty or chalky grit	Wash surfaces thoroughly with water
Fungal decay	Visible to naked eye	Dark fouling	Determine cause and remove, may need to remove and treat chemically
Cracks	Visible to naked eye	–	Depending on type of crack, spakle entire surface, then reinforce with crack covering or elastic fabric
Absorbency	Moisten with water	Too absorbent: turns dark quickly Not absorbent enough: Water forms beads	Too absorbent: apply primer Not absorbent enough: sand or apply primer
Sinter layers	Scratch or sand layer, then moisten with water	In case of dry base surface: glossy surface and minimal absorbency. After water test, scratched area turns darker	Sand away sinter layers