After the cold spell temperatures are beginning to rise again above 5 degrees! This has got lots of people asking how does K Rend accelerator work.
K Rend Accelerator is a liquid additive used to reduce the waiting time before scraping K Rend scraped texture renders. It accelerates the curing time of K Rend scraped texture renders meaning that the render may be scraped earlier, enabling a faster completion of the job. K Rend Accelerator may be used in cold conditions to improve the scraping time (however all winter working precautions still apply).K Rend Accelerator has no effect on the appearance of the K Rend scraped texture render if the render is scraped at the correct state of readiness or hardness.
Standard UF Base, UF Fibre Base, HP12, HP14, HPX Base Primary coat, where required, should be applied to substrates as preparation for subsequent coats of K Rend scraped texture finishes. Thickness should be as per product specification. It is important to take special care to straighten with a darby / straight edge to ensure that the next coat is applied to uniform level. Form a light key only. If you are applying K Rend Silicone TC as a finish coat, do not form a key and leave the base coat flat and smooth. Allow 24 hours curing time before further application, unless advised otherwise, for instance it is recommended to allow 14 days curing time before the application of K Rend Silicone TC top coats to guarantee adhesion. For info on unusual substrates, seek technical advice.
Base Coat Recommended Thicknesses
4-6mm: HP12, HPX
8-10mm: UF, UF Fibre Base
K REND SCRAPED TEXTURE
Silicone FT, Silicone Spray E Grade, K1 Spray, K1 Silicone
ONE COAT / FINISH COAT
One coat is applied directly onto block work (please seek advice from our Technical team) and must be finished to a minimum of 16mm thick to avoid ‘ghosting’. The material should be applied 18mm thick in 2 passes; the first pass 6-8mm and the second pass 12 - 14mm. (See also under Spray Application). After setting, 2mm is scraped off for a 16mm finish. If the material is being used in a two coat application the Finish Coat is applied over a K Rend Base Coat to line level, using a darby or straight edge, to a minimum thickness of 10-12mm When straightening, hollows should be filled out immediately before a skin is formed. Care should be taken to avoid small hollows, which can make it difficult to achieve a good finish. Small areas such as quoins, reveals and bands can be left with a plastic float finish. Do not polish.
Finish Coat Recommended Thicknesses
16mm: 1 Coat
10mm: 2 Coat Over base coat (Base coat recommended thicknesses above.)
SCRAPING
Scraping should take place when the render has set but not fully hardened. The exact timing varies according to weather conditions; can be anything from 4 to 36 hours after application. Typically, in moderate conditions, the render should be scraped the day after application. The render is ready for scraping when a thumb impression cannot be made but it can be marked with a thumb nail. At the correct time, the aggregate scrapes easily from the wall and does not stick to the scraping tool. Scraping should always be done lightly in a tight circular motion to produce a uniform finish. Remove only 1 - 2mm from the complete surface. All areas must be scraped at the same time.
K REND SILICONE TC
Please click here to download K Rend Silicone TC application instructions PDF.
First Coat: K Rend Basecoat
Preparation Coat: K Rend Primer TC
Final Coat: K Rend Silicone TC
Ensure that the background is clean, level and dry with no signs of efflorescence. We recommend newly applied basecoats are allowed a minimum of 14 days to cure.
Ensure all adjacent surfaces are well protected and masked. (Windows, sills, doors, floors, glass, brickwork etc.)
Application
Apply K Rend Primer TC (Colour matched to topcoat) by brush, roller or spray. Ensure that 24 hours drying time is allowed before the application of the topcoat.
Apply K Rend Silicone TC topcoat to the thickness of the largest grain size using a stainless steel float and allow to take up slightly. (This is only a few minutes.) The surface is then rubbed up in a circular motion using a plastic float to create a uniform texture.
Ensure that you complete full surfaces in a continuous motion without interruption. Maintain a wet edge at all times.
To avoid run off, protect freshly applied render from rain and drying too fast. Drying times will be prolonged, sometimes quite drastically, by low temperatures and/or high humidity.
MACHINE APPLICATION
The following K Rend products can be spray machine as well as hand applied; Silicone Spray E Grade, K1 Spray, K1 Silicone, Overcoating Silicone Dash, Silicone Spray Dash, Silicone Tyrolean, Standard UF Base, UF Fibre Base, HP12; HPX Base. M-Tec spray machines are available to purchase or rent from K Rend. A technical advisory service is also available.
The use of timber cladding and elaborate wood detailing in new builds and refurbs seems to be on the increase in a big way. When wood is skillfully used in a contemporary design along with a great looking render such as those by K Rend or Parex the results can be stunning.
Unfortunately, in a lot of cases this stunning look may only be temporary as one key problem seems to be getting overlooked time and time again if the regular calls our Mendrend technical team receive are any indication.
A lot of the pressure treated timber on the market appears to be treated with a substance that is not completely water proof so when the timber gets wet the wood stain is then dragged down the wall which then pentetrates deep into any surface that is porous such as your normal cementitious render. The results can be devasting and extremely difficult to correct. We strongly advise if you are considering the use of treated wood in the design of you build that you check with your wood supplier that the treaments used in its production are completely stable in the presence of water or consider the use of an additional wood seal that makes the timber completely impervious to water.
We've specialised in repairing renders for many years now from the design and development to on-site application of our specially designed patented Mendrend range of products we have been focused on customer service as a core driver of our business.
During our time as render repair specialists prior to our focus on the supplying of materials we quickly realised that there is a key grey area when its comes to render applicators and the manufacturers warranties that are provided when renders are correctly applied. This grey area is building settlement; if a building settles (The vast majority don't but any building can.) and cracks after render is applied it tends to be the applicator who is blamed when in fact its absolutely no ones fault the issue has occurred. The applicator may then call the manufacturer in to see if the issue is covered under the warranty only to be correctly told that settlement is not covered under their standard warranty terms. This would be the case for pretty much any render system sold on the market today.
This usually results in the applicator / builder / customer going round in circles trying to solve problem and one of them ends up having to pay to correct the issue depending on who loses the argument!
Our no quibble crack free guarantee provided when we supply render systems is designed to solve this age old problem. We have teams of technicians who operate nationwide assisting customers and resolving disputes daily. I'll be frank we don't aim to be the absolute cheapest render supplier out there, I'll leave that to the guys who cannot provide their customers with assistance or have no idea what they are selling. We aim to provide low competitive prices whilst providing help when needed.
We invite all our applicators to offer this guarantee to their customers and maybe offer a cheaper price without this guarantee if a cheaper supplier is available and let the customer themselves decide.
We invite all our customers looking to have their own properties rendered to strongly consider our industry leading backup service for what tends to be a small addition to the price of having the works done.
Those who have ended up actually needing repairs done have found our service to be invaluable. A simple crack which normally could have been a problem to fix suddenly becomes a simple phonecall. This service is currently implemented on large housebuilder sites such as Taylor Wimpey, Arncliffe Homes and Cyden Homes with great success.
If you have any questions about how you can provide your customers with better service please contact us.
The phone has rang a couple of times this week with customers a little flabbergasted that the thin coat render they applied a few days ago has washed off in the last rain shower with a slightly accusatory tone in their voice.
All I will say on this matter is that there is nothing wrong with the material when this happens, and its not unusual for customers to start flagging this issue up at this time of the year, as its the same every year. The simple fact is that some thin coat renders perform better in cold and damp conditions than others and each job needs planning accordingly.
Traditional thin coat resin based bucket renders generally depend on good air drying conditions as there's no curing process with these. If the air is constantly cold and damp they struggle to dry if not protected and can hang around for days only for a rain shower then take them off the wall in a hair curlingly frustrating fashion. They will dry in cold (5c+) air if the air is dry and crisp and the background is dry, but it may still need a good 24 hours before it is considered safe from the weather. Be careful with these at this time of year, a weather shielded scaffold and a space heater goes a long way to alleviating some of the problems cold damp weather may bring with these types of renders.
The new mineral thin coat renders such as K Rend Mineral TC perform better in colder conditions with less risk of washing off because they cure and are much less dependent on good air drying conditions to harden. They still need to be applied on a dry background, but a bit of fog or moisture in the air won't prevent them from going off completely and drying times will be measured in hours rather than days. Temperatures still need to be a minimum of 5c on a rising thermometer. This is an excellent winter alternative to a traditional thin coat render if you have a job that needs to be done!
If you have any questions or need advice, please contact us!
We have briefly mentioned in previous blog articles some of the benefits and reasons you might want use an external render system, but it is worth further elaborating on these points and more as to why rendering an external wall is beneficial to a property.
Improve the external appearance of a property
There’s no denying that applying a render system to an old, tired-looking building will transform its appearance – making it look modern and more visually appealing. Local authorities will often use render when renovating their properties for this reason.
This aesthetic improvement can be beneficial in multiple ways – if you live in the property - it makes your home look nice. If you looking at selling a property, it can make it look more visually appealing to potential buyers.
From a wide range of colours, to a huge selection of textures and finishes, there are a wealth of possibilities available when rendering a house.
Increase the thermal efficiency of walls
Some renders – like the K Rend Silicone Thin Coat range – can be used as part of an External Wall Insulation System. While most render systems themselves are not classed as insulating (though they do provide a small amount of innate insulation), when used as part of an EWI system they can help increase the thermal efficiency of walls and reduce heating bills – not to mention the other benefits featured in this article.
Weatherproofing
External walls that are in a poor condition can lead to the ingress of water and external debris which will worsen if left untreated. The use of a render system on an external wall forming a barrier, protecting a building from the elements. These renders incorporate water repellent technology, protecting against water whilst still allowing the substrate to breathe.
If you need help with applying render or you would like to know more about the benefits of render, contact our experts today.
Render systems are available in all sorts of colours, styles, finishes and textures and whilst they all vastly improve the appearance of a building, their suitability and appropriateness vary from factors such as the building substrate to planning regulations of the local authority.
What types of render texture finishes are possible?
Each manufacturer has renders with different finishes, and the look you wish to achieve will influence the render system used.
Textured, Smooth, Scraped and even more unique finishes such as brick effects or ashlar detailing are achieved via a combination of the application method and the finishing tool used.
How are different texture finishes achieved?
Standard renders usually have 3 categories of finishes - scraped, smoothed and textured – each with their own subtle variances. For example, Parex Monorex can be scraped to achieve a fine or medium finish.
Scraped texture finishes are achieved by scraping the render with a scraping tool before the render has set hard whereas using a trowel or float will result in a smooth-looking finish.
Applying the render using a spray machine will give a far more pronounced texture finish, similar to tyrolean and roughcast.
There are also more technical and specialist finishes such as pebble dash where an aggregate is thrown onto a wet receiver; and brick or ashlar effects, where a pattern is cut into wet render to give it the appearance of real brickwork.
Guidance on choosing the best texture finish
For advice on achieving the right texture finish, or if you would like guidance on choosing a texture finish, contact our experts who are always ready to help.
The result of a well-applied render system is a fantastic looking finish, designed to give old and tired-looking exteriors a new lease of life.
However, this is only true if the chosen render system - such as K Rend - is applied correctly. Incorrect application can result in the failure of the render system, requiring it be replaced. One of the main factors of a poor quality K Rend render system is due to the applicator not having sufficient knowledge of how to apply K Rend.
Always Follow Manufacturer Guidelines
Rendering an exterior surface is a technical task but its payoffs are well worth it – a fantastic looking exterior finish with additional benefits such as weatherproofing and improving the visual appearance of a tired, old building.
People may be put off using products such as k rend insulated render systems due to the horror stories that have come about due to applications performed incorrectly either from lack of experience or failure to follow manufacturer guidelines. If applied correctly, problems like the infamous Curse of "Halo Ring" can be easily avoided.
Different Methods Yield Different Results
The application of k render systems affects their appearance, both in how it is applied and how it is scraped – just take a look at our blog post on Why You Should Always Provide a Customer Test Panel. In order to achieve the best results, it is essential that the render is applied in accordance with the official K Rend instructions.
Use an Expert for Expert Results
Our qualified technicians are experts in applying K Rend and can help rectify any mistakes or issues that occurred during a previous poor application. Contact us today for help and advice on k rend application.
As we have written about before, large cracks in render can be an indication of a major problem in the substrate. However, smaller and much less serious fissures can also appear. These fissures tend to be a lot smaller than cracks (around 0.1-3mm in width)
Origins of fissures in render
Like cracks, fissures can occur due to movement from the building or the substrate the render has been applied to. Whereas large cracks tend to be an indication of a more severe issue, minor fissures usually occur due to minor inconsequential movement in the substrate.
What to do if you find fissures in render
It goes without saying, but you should always seek the advice of a professional before attempting any repairs. Determining the origin of the fissure is essential to ensure that there are no recurring instances of the problem. It is also advisable to wait for a period of at least 6 months to make sure that all fissures in the render system have stabilised.
Repairing fissures in render
Our patented Mendrend Flexible Fissure repair system is specifically designed to repair fissures in render from leading manufacturers and is supplied in a range of colours intended to match render manufacturer colour ranges. We also provide a comprehensive support service for this product.
One thing some applicators are better at than others is providing their customers with sample test panels of a finished render product as it can cause big problems with customers who are expecting their render to look exactly like it does in the brochure or even worse on their computer monitors!
The two render samples shown in the above picture are made from exactly the same render from the same bag. The sample on the right was simply scraped much earlier during the drying process than the render sample on the left and the difference that can make on the outcome of the final colour of all cementitious renders can be quite profound. It is for this reason we strongly recommend that you complete customer samples so you can test and verify the colour with them before ordering any materials
It is very common for applicators to scrape renders early, therefore the colours achieved on site could possibly be much stronger than the colours of manufacturer provided samples which are made in a laboratory under ideal circumstances. It should be noted that all manufacturers of cementitious render products would deem this to be normal behaviour of the product.
We are happy to provide assistance with this, please feel free to contact us!
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