Focus on floors: your questions answered

A selection of the hundreds of questions answered by F. Ball’s technical team in the past few weeks

Q. What levelling compound should I use for an outdoor area where forklift trucks will be used?

A. Stopgap 850 Exterior is F. Ball’s levelling compound for external applications. Once cured, it is unaffected by rain or frost. It can be used to smooth and level rough or mechanically damaged concrete or sand/cement screeds that have become worn, impact damaged or weathered. It can also be left as a standalone exterior wear surface.

Q. I am looking for a high temperature adhesive to install LVTs over a sand/cement screed with underfloor heating.

A. There’s no need for a high temperature adhesive where underfloor heating is installed unless the floorcoverings will be subject to extreme temperatures/temperature changes. However, you need to make sure that underfloor heating is turned off for at least 48 hours before, during and after the installation of floorcoverings. A pressure sensitive adhesive is recommended when installing LVTs. They offer instant grab upon contact so that tiles or planks won’t move about when working, helping with the alignment of complex designs and patterns. If a temperature tolerant adhesive is required, in areas where extreme temperatures or temperature changes may cause vinyl tiles or planks to expand and contract, leading to tenting and gapping over time, F. Ball’s Styccobond F49 Hybrid PS is recommended. The solvent-free adhesive offers pressure sensitive characteristics, whilst developing the ultra-high bond strength required to hold floorcoverings firmly in place over a wide range of temperatures (as low as -20°C up to +60°C).

Q. Stopgap P131 primer is absorbing away into the sand/cement screed I’m applying it to.

A. Contractors should prime internal, absorbent surfaces with Stopgap P131, F. Ball’s general purpose primer, diluted with four parts clean, cold water to every one part primer. On particularly absorbent surfaces, further application of Stopgap P131 may be necessary. Apply one or more coats of dilute primer, but avoid applying too much so that puddles form.

Q. Can I apply Stopgap F77 waterproof surface membrane over a subfloor with bitumen residues and well bonded VA tiles?

A. Stopgap F77 should be applied to a clean substrate. In situations where screeds are rough, uneven or damaged, it’s recommended that a moisture tolerant levelling compound is applied before the application of a waterproof surface membrane, to avoid it pooling in undulations, compromising the integrity of the membrane when cured and adding cost. In this scenario, F. Ball’s Stopgap 1200 Pro levelling compound is ideal because, apart from being moisture tolerant, it can be applied directly over old adhesive residues, including bitumen and carpet tile tackifiers, removing the need to mechanically prepare the subfloor. The levelling compound should be left for a minimum of 24 hours prior to the application of Stopgap F77.

Q. What adhesive should I use for installing wood blocks?

A. Styccobond F21 is F. Ball’s traditional, high temperature bitumen/rubber dipping grade emulsion for installing wood blocks that are at least 12mm thick. It’s non-flammable, solvent free, protected against bio-degradation and suitable for use over normal underfloor heating installations. It can be applied to Stopgap levelling compounds, structurally sound, smooth, dry, absorbent subfloors of concrete and sand/cement screed and plywood (minimum 6mm flooring grade). If a dipping grade adhesive is not wanted, then the trowel applied Styccobond B95 adhesive can be used instead.

Q. I want to install LVTs over ceramic tiles. What preparation is required?

A. Start by making sure the subfloor is suitably sound and the ceramic tiles are well bonded. Also, check subfloor relative humidity levels; if they are less than 75%, no waterproof surface membrane is required, and you can proceed to priming. Use F. Ball’s Stopgap P141 primer, which is specially formulated to create a textured finish to enhance the bond formed between non-absorbent subfloors and subsequently applied Stopgap levelling compounds. For perfect results when installing LVTs, apply F. Ball’s Stopgap 300 HD levelling compound to create a perfectly smooth base for the receipt of floorcoverings. Its high compressive strength makes it ideal for where designer flooring will be subject to heavy loads or high foot traffic.

Our technical team are on standby to answer questions about your projects and F. Ball products from 8.30am – 5.00pm, Monday to Friday.

Please note: site conditions vary. Don’t rely on these specific responses for your own project. If you are unsure about any technical issue relating to specific flooring installations, contact the F. Ball Technical Service team on 01538 361633 or consult the product data sheets available from F. Ball’s website.