grouting techniques

[Dave]

Specialist Applications
If your tiles will come into contact with water, or hygiene areas such as kitchen worktop food preparation areas, tiled areas which are subject to public hygiene restrictions (BS) or need to be acid or alkaline resistant, an epoxy-based grout must be used. Epoxy grouts should also be used for metal tiles, and even tiles with a metal substrate. For commercial applications, an epoxy grout may be specified for other specific reasons. It is also recommended that epoxy grout is used in shower bases in particular to avoid the possibility of water migration behind the tiles and causing problems.
These grouts are significantly more expensive that the general-purpose grouts, and greater care must be used when removing grout residue a s any epoxy left to cure on the surface of the tiles will be extremely difficult to remove -special grout remover may need to be used to clean the tiles afterwards. It is recommended that the services of a professional with experience of epoxy grout systems should be used for this type of application. You may also find that the professional will often specify a manufacturers material to use, as the characteristics and working methods tend to differ from manufacturer to manufacturer.
Note that suitable protective gloves should be worn whenever using epoxy grout systems as it is not advisable for this type of material to come in direct contact with the skin.
APPLICATION PROCEDURE

The following mixing and application method is applicable to 'slurry grouting' which is the easiest and best method most commonly used where the tile surface can be easily cleaned afterwards. However, if you are laying a highly marked natural stone or terracotta (rough side up), where you do not wish to fill the 'indentations' etc. with grout, it is more appropriate to mix the grout to a thick 'dryish' paste, and use a conventional pointing technique as used for normal house brickwork.
General Precautions

All necessary movement joints such as the surrounds of baths etc. should either be initially filled with suitable flexible mastic/silicone, or protected to ensure excess grout is not allowed to accumulate and set.
If applying grout to natural stones or unglazed tiles, ensure that an appropriate coating of sealant has been applied before grouting to aid cleaning of the tile surfaces.
Always ensure that mixing containers and tools are clean and free of previous grout mixes.
Always mix the grout with clean water free of contaminants such as salt etc.
Do not mix grouts of different types and manufacturers, and do not mix with cements or limes etc.
Read the manufacturers instructions to ascertain the ‘pot life’ (working time) and bear this in mind when mixing up a batch of grout. Ensure that you are able to apply all the material mixed prior to the pot life being exceeded.
Preparing the joints

Before grouting, check that the tiles are well fixed, and in the case of fixing with traditional mortar, that the minimum waiting period of 7-10 days has passed as this allows for the removal of the moisture and therefore the soluble salts. The joints to be grouted must be dry, clean and free of dust and foreign matter. They should be clear for at least 2/3 of the depth of the tile – any excess mortar or adhesive must be removed.
Preparing the grout

Whilst stirring pour the dry powder mix into a clean plastic bucket containing a small quantity of clean water (refer to manufacturers instructions for details of quantities). Mix until a smooth creamy paste is obtained. If available, use a slow speed mixer (maximum 150 rev/mm) to prevent the excessive formation of air bubbles.
Leave the mix to stand for 2-3 minutes and then remix briefly before use.
The working time of the grout changes between different types and manufacturers, varying from anything between 30 minutes to a few hours.
If the grout starts to set before applying it to the tiles, do not add more water, simply discard and clean out the mixing container before making up another batch. After completing your work, ensure that any material left is removed from your container, and that the container is cleaned before the grout has cured.
Applying the grout

WARNING : If you are grouting over metallic tiles, great care should be taken not to cause abrasion of the glaze with the grout mix.
Always use the same method of working to obtain uniform results. Where the tiles are absorbent or the ambient temperature is very high lightly dampen the surfaces of the joints with a wet sponge before applying the grout.
Fill the tile joints with the grout paste using either a hard rubber float or squeegee without leaving voids or gaps.

Remove the excess grout from the surface by drawing the float diagonally across the joints whilst the paste is still fresh.
Leave the paste to firm up in the joints until it is no longer plastic.
Clean off the surplus grout with a damp hard cellulose sponge working diagonally across the joints without applying any pressure. Rinse the sponge frequently preferably using two buckets of water; one for removing the surplus paste from the sponge and the other for just clean water for the final rinsing of the sponge and moistening new ones. Use a special grouting sponge – the proverbial bath and household sponges rapidly fall to pieces become quickly overloaded with grout.
The final cleaning of the residual film of grout powder from the surface of the tiles should be carried out using dry waste paper or a clean dry cloth after the grout has set.
If the cleaning off is carried out too quickly (when the paste is still plastic) it is possible that the grout will be partially removed from the joints. On the other hand, once the product has set hard, cleaning by mechanical means will be necessary which is very difficult and likely to cause damage to the surfaces.
Protection and Finishing

Do not allow traffic onto the tiles, or subject to excessive water or extremes of temperature until the grout has fully cured – refer to the manufacturer’s instructions. If the material being used is a natural stone, terracotta or unglazed tile, then after cleaning, apply one or more further coats of sealant and finish with appropriate polishes etc. as applicable.
Cleaning

Again, read manufacturers instructions, but generally, cement based grout can simply be cleaned from tools etc. with water, and cleaned from the hands with soap and water. Epoxy grout should not be allowed to harden and should be removed from all of your tools while it is still in a liquid state. Suitable protective gloves should be worn whenever using epoxy grout systems as it is not advisable for this type of material to come in direct contact with the skin.

hi

every time i talk to a tiler about epxoy grouting, their faces screw up and they say, ' 'sterr clear of it'...why is it so difficult to use?? does it takes long to master??

cheers
ed

[grumpygrouter]

Originally Posted by tiler burden

hi

every time i talk to a tiler about epxoy grouting, their faces screw up and they say, ' 'sterr clear of it'...why is it so difficult to use?? does it takes long to master??

cheers
ed

Had a demo of epoxy grouting from a BAL technician, you need to you a hard rubber float and work quickly because, like rapid set addy, goes off very quickly. At the same time, cleaning off residual grout is important as again it sets very quickly, the guy doing the demo was using a BAL white emulsifying pad to remove the residue as it had gone off in about 4mins on the surface of the tile. He told me it is better if 2 guys work together when using epoxy as one can fill and the other can clean as they go along. Tools are usually disgarded afterwards too. The guy was sweating quite heavily after only a few minutes because it was hard work!

Grumpy

[pjc]

I think the term used is poxy grouting they all seem diffrent some are easier than others to use easier not easy

[Dave]

the modern day easypoxy grouts are easier to use than the ones i used years ago that was like spreading chewing gum and even harder to remove..todays epoxy's are much easier to use and wash off with warm water and an emulsifying pad as mentioned by grumpy..the trick is to give it one wash before it dries on to tile surface then leave for a while before washing again and then buffing once dry...

[pjc]

your right there Dave the gum days Also i do the last wet clean with a flat lint free coth

[Dave]

true pete ..cloths are good for last clean up as well....

so errrmm its a bit like plastering lol.....now do you see why i want to be a tiler ha ha

thank for the help ;0)

[pjc]

wish it was that easy

[stuart69]

what about these grouting guns? has anybody used one and how the hell do you fill it ?

[whitebeam]

Grout guns, never again, mix up the grout pour/place into tube, mine kept blocking and grout ended up squeezing out of the joint between tube and nozzle, crap. Darren at nett sells grout bags never used one but can't be any worse than the guns. Someone may know an easier way.

[Ric]

i found that even the grout bags clog up, and they are a nightmare to fill up! think you need some time to get used to this technique, but i guess it will pay off as keeps the tile clean as you go, especially slate with all its little ridges etc.