Our pleasure.

Nice to hear from you. It would really depend on the nature and reason for the cracking. Do you have any images, and a plan where the cracks run from and to? I would be happy to take a look for you. Regards Andy

The simple answer is yes. The cracks would need to be assessed, but if suitable for repair a low viscosity resin could be used.

Thank you for your kind words Mark. If you need any further help please let me know.

Nice to hear from you. There are various factors that come into play, however in heavily trafficked areas bonded screed is the preferred option.

Nice to hear from you Jim. BS8204-1:2003 talk about ratio by weight. Therefore you could use the buckets, but weigh and mark the same weight for both sand and cement buckets. In terms of volume of water, you will need to use the snowball test (make a ball in your hand to test if you have enough water in the mix). Not to wet or dry. Experience will help with this part of the process. Simply mixing a set weight/volume isn't going to work. Start the pan mixer once all the materials are in. I hope this help. Regards Andy

Glad the video helped.

Thank you kindly!

Nice to hear from you Johny. It all depends on the bay size, shape of the room, and aspect ratio. A general rule of thumb for stress relief joints is 5m to 6m intervals. A heated levelling screeds typical maximum bay size would be 40m2. The fibres will minimise shrinkage cracking, however stress relief joints are still required. I hope that helps. Regards Andy

So nice to hear from you. Really depends on what the substrate is? Assuming you concrete, then a waterproof membrane. Gypsol TS15 will go down to only 15mm. www.speed-screed.com/knowledge-centre/gypsol-ts15/ What depth of screed were you looking for? Regards Andy

You are most welcome. Thank you for taking the time to let us know. Regards Andy

Thank you for the question Christoffer. Due to the nature of it I passed it onto my good friend Mike Rhodes at Ronacrete. This is his thoughts: I am less concerned about wear resistance of the screed, although snow chains will caused greater wear than typical heavy duty traffic, than I am about a the effect on insulation boards of dynamic loads imposed by 3 tonne vehicles, particularly where loads are transmitted through a nominal thickness of 40mm (very close to the minimum Ronafix floating screed thickness of 35mm), considerably increasing load transmission to the insulation, just at the point where vehicles transition to and from the ramp. Ronafix Pre-packed Wearing Screed 15mm+, two component factory produced polymer modified granolithic wearing screed, bonded to the prepared substrate with Ronacrete Standard Primer, two component factory produced polymer modified slurry primer, is most suited for this application. Minimum and nominal floating polymer modified screed thickness Ronafix polymer modified screeds may be used thinner than is specified by BS 8204 Part 1 because of the superior essential characteristics conferred by the Ronafix polymer. The minimum thickness of a polymer modified floating screed is 35mm, when the insulation board is strong enough to accept transmitted loads without deformation. To ensure that a minimum 35mm thickness can be achieved, the nominal screed thickness may have to be ≥ 50mm, depending upon the specified surface regularity of the screed and substrate levels variation. SR2 surface regularity allows variation of 5mm under a 2m straight edge and allowable concrete slab levels variation may be ≥ 10mm. The following is from BS EN 13813 Screed material and floor screeds - Screed material - Properties and requirements Table 5 - Wear resistance BCA classes for cementitious and other screed materials BCA Class AR6 AR4 AR2 AR1 AR0,5 Maximum wear depth in microns 600 400 200 100 50 Ronafix Pre-packed Wearing Screed 15mm+ wear resistance Wear resistance of Ronafix Pre-packed Wearing Screed 15mm+ has been independently tested and achieved AR0.5 (the greatest resistance to wear) when subjected to the BCA test procedure in accordance with BS EN 13892-4. Water Permeability. Test Authority: British Precast Concrete Federation. Freeze/thaw cycling. Test Authority: British Precast Concrete Federation. Ronafix 3:1 mortar, p/c = 1:10. 24 hours -18°C/+20°C Cycles Flexural strength N/mm² Sample 1 Sample 2 Control 1 Control 2 0 10.8 11.6 7.2 6.0 15 4.5 3.2 30 10.5 0 0 60 11.0 120 10.9 10.5 He may have meant phenolic insulation and the strongest Kingspan insulation made with phenolic foam is Kingspan Kooltherm® K103 with a compressive strength@ 10% compression of 120 kPa, likely strength @ 2% compression 50-60 kPa (60kPa = 0.06N/mm2, 1,000 times weaker in compression than Ronafix Pre-packed Wearing Screed 15mm+, two component factory produced polymer modified granolithic wearing screed Compressive Loads - quotation from Kingspan brochure “Un-reinforced floor screeds can be used in conjunction with Kingspan Kooltherm® K103 in most applications. The compressive strength of Kingspan Kooltherm® K103 offers considerable advantages over some other floor insulants. Providing a minimum compressive strength of 120 kPa at 10% compression allows greater floor loads to be considered and therefore additional scope in the use of Kingspan Kooltherm® K103. However, where floor loads are to be excessive, consideration should be given to the use of Kingspan GreenGuard® which has greater compressive strength. For further information please contact the Kingspan Insulation Technical Service Department (see rear cover).” Deformation of Insulation Deformation of insulation under point loads is likely to damage a screed. 120-150kPa (0.15N/mm2) boards are popular for floating screed application and are adequate for residential use at traditional floating screed thickness but may not be strong enough for vehicle loads, even when loads are transmitted through an 80-100mm thickness of screed. Floor insulation boards are designed for use with ≥ 75mm thickness of screed and thinner screeds will transmit higher loads to the insulation. It is likely that only a higher strength polystyrene void former or foamed glass insulation will be suitable for the loads transmitted. A structural engineer must be consulted to determine insulation strength required for avoidance of screed cracking. The following are benefits of Ronafix polymer modified screeds  Improved strength gain and 28 day strengths in new screeds  Suitable for wet areas  Suitable for exterior application  Greater durability, tensile and flexural strengths are maintained for decades longer than in traditional screeds, see the durability paragraph below  Reduced minimum thickness for bonded, unbonded and floating screeds  Reduced shrinkage  Low water absorbency, making screeds resistant to frost attack. Polymer rich mixes will not allow passage of water under hydrostatic pressure  Some mix designs suitable for use as medium to heavy duty wearing surfaces  Suitable to be laid to falls  Faster drying than traditional screeds and calcium sulphate screeds  Compatibility with resin floorings, unlike traditional screeds and calcium sulphate screeds  Superior corrosion protection of embedded steel; calcium sulphate screeds are not compatible with embedded steel Comparison of key strength data in 3:1 sand/ cement and polymer screeds and % improvement in strengths of polymer screeds compared to 3:1 sand/ cement Screed type Tensile strength % improvement in tensile strength Flexural strength % improvement in flexural strength Sand/ cement 3:1 3 N/A 7 N/A Ronafix Pre-packed Wearing Screed 15mm+ 6.5 > 115% 11.5 > 60% Strengths quoted in N/mm2 Ronafix Durability Ronafix has been used to improve the performance of high strength mortar for more than 50 years. Five decades of use and accelerated ageing test both show that Ronafix admixture considerably increases mortar durability. The following is a table showing results of testing of mortar 3:1 sand: cement with 9 litres of Ronafix polymer admixture and additional water to produce workability. Samples were heat aged at 700C for up to 365 days to simulate ageing to BS 4551:1970, BS 12: 1972. 365 days testing is approximately equivalent to 260 years UK service life. Flexural strength of unmodified control samples remained at approximately one third of Ronafix mortar strength and tensile strength of unmodified sample fell to 0.7N/mm2 by 20 years equivalent ageing and became unmeasurably low by 40 years equivalent ageing. Ronafix Samples Unmodified Samples Accelerated age of sample Flexural strength Tensile strength Flexural strength Tensile strength 20 years equivalent age 10.5 3.5 7 0.7 40 years equivalent age 15.5 3.0 4.9 Unmeasurably low 80 years equivalent age 14.7 2.0 5.5 Unmeasurably low 260 years equivalent age 14.1 2.3 5.4 Unmeasurably low All strengths expressed in N/mm2 Slip resistance of Ronafix wearing screeds Slip resistance of Ronafix Pre-packed Screed 6-50mm was determined using “SlipAlert” equipment (ramp/trolley method, please see BS 8204-3, page 25 Annex A1 - Determination of slip resistance of pedestrian surfaces by the ramp/trolley method, alternatively known as the roller coaster method), results below 130 are deemed to have achieved low slip risk. The table below shows values achieved and equivalent Pendulum Test Values (PTV). PTV ≥ 40 is regarded as low slip risk. Slip Resistance Ronafix Pre-packed Screed 6-50mm Steel Float Finish Test Conditions Test Method Specimen 1 Specimen 2 Specimen 3 Specimen 4 Dry SlipAlert 115 115 115 117 µ 0.64 0.64 0.64 0.6 PTV 58 58 58 55 Wet SlipAlert 121 124 125 126 µ 0.52 0.48 0.47 0.46 PTV 49 46 45 44 Slip resistance of Ronafix Pre-packed Wearing Screed 15mm+ is similar.

Hi Steven, It sounds like the adhesive is bitumen, which can also be used a DPM. Few adhesives and screeds will bond directly to bitumen, however there are some. Now you have removed the tiles, what are you looking to do next? Regards Andy

@@SpeedScreedLimited. I will be self levelling the floor in preparation to ceramic floor tile kitchen and hallway, I just want to be sure of what self levelling compound to use , this product looks like it would be suitable , would be grateful of your advice Andy cheers 🤞👍

Hi Steven, As with all thin screeding products they rely 100% on the bond between the screed and substrate. As long as the bitumen is sound, you shouldn't have any issues. If it isn't then you will need to remove, however bare in mind it may have been used as a DPM. Given a sound substrate you will be good to go with Arditex NA. I assume the substrate is concrete? Regards Andy

@@SpeedScreedLimited Thanks Andy , the bitumen is dry and solidly stuck to the screed , I will use this product your advice was very helpful👍👌

Let me know how you go on. Regards Andy

Hi Namso, There may or may not be a requirement for an admixture. The use of an admixture is when the certain performance parameters are needed, fast drying, rapid strength etc. The dosage of any admixture will depend on which product is used. Regards Andy

Am using 1kg of cement, so i want to know the quantity of admixture to be used. Thank you

Hi Namso, What would you be using an admixture for? What would the admixture be doing? If you can let me have some back ground on what the project is and what you are trying to achieve with the screed (details of substrate, thickness, and final use would be helpful. Regards Andy

Nice to hear from you Namso, working from BS EN 13139 for 0/4mm it is as follows: Sieve size first: 5.6mm 95-100%, 4mm 85-99%, 0.5mm 30-70% passing (this is medium rather than course). As always you are wanting to be filling the gradings gap, and well graded sand will give strength and a good finish. Hope that helps. Regards Andy

@@SpeedScreedLimited thank you. But remaining the ratio of the materials used.

Good Morning, I am so sorry to hear about your issues. It would be interesting to find out if your have problems with moisture, however if the screed is all "crumbled and broken" then there is certainly issues with either the screed or the substrate below the screed. Do you have any images I could take a look at please? If you could also let me know what the floor make up is (hardcore/membranes/concrete/insulation/screed along with an depths of those products would be helpful, I do understand that you may not know this). My email address is [email protected] and I look for ward to helping. Regards Andy

Thank you for your question. Underfloor heating is perfect for use in a gym, as long as the screed is designed for that use. The screed will need to take the load imposed by the gym equipment. A further consideration would be the insulation design, which would need to once again match loadings. As long as the correct products are used, there is no issue.

Thank you for your question Happytravelguy. I recorded you a video in answer to your question. Please click on the link. If you have any further questions please let me know. Regards Andy Speed Screed Ltd vidmails.com/v/xZ9WsKndk6

@@SpeedScreedLimited WOW, thank you so much for your time and the video explaining the options.⭐️

@@biblebasics100 You are most welcome! Anything else you need, please let me know. Good luck with your project!

Hi Liam, Nice to hear from you, sorry you are having some issues. I have a few questions. 1. You are now going to be bonding 10mm of sand and cement screed to the concrete? If so what mix are you proposing to use? 2. Your concrete was laid a couple of days ago, and you have the course aggregate from the concrete on the surface? 3. Did you mix your own concrete? 4. Was the concrete cured? Curing agent or membrane? If you could let me know help. my email is [email protected] if you want to send some pictures of the concrete so I can get a better idea of what is happening. The substrate has to be fit for purpose to take anything bonding to it, 10mm of screed wouldn't make a poor concrete a good concrete if there is a problems with it. I look forward to hearing from you. Regards Andy

Nice to hear from you. What are you wanting the screed to do? Bond with the decothane or just sit on top? How thick is the screed going to be? Just trying to get a feel for what you are wanting to achieve.

Thank you so much for your positive comments. If you are ever available in the future, please get in touch. We are always looking for the best screeders.

Hi Laura, there are a number of products that will allow between 20-60mm bonded. Keracem Eco, Topcem, Retanol Extreme to name a few. Let me know if you need any more help.

Most welcome!

Glad it was helpful!

Thank you for the question. Semi dry screed works perfectly well with underfloor heating. Flowing screed has a greater thermal conductivity, and so performs a little better. In all other respects either product will do a great job. Hope that helps.

Hi Sam, Typical drying time for a traditional semi dry are 1 mm per day up to 50mm and then an increased time after the 50mm (as per the BS8204-1:2003). So for a 70 the minimum time would be around 70-90 days, and at 100 mm it would 100-150 days). The conditions on site temperature and humidity will affect the drying times. The only way to know 100% if you screed is dry enough for those tiles is to moisture test it. Hope that helps.

The next day but used SBR bonding liberally

Hi Paul, Maximum depths of latex screed vary from product to product with most being 10mm, however when mixed with aggregates the maximum can extend to 30mm for some products. Always check with the supplier.

Nice to hear from you Jonathan. Just to confirm the "cracks in a screed" is the original concrete floor slab? Not an overlay of screed onto the concrete? Assuming that we are talking about the concrete base, you certainly wouldn't expect it to start cracking with just chairs on the surface. Before painting was the concrete is good condition, and the cracks have only appeared with the chairs? If you have any pictures, before and after, showing the layout of the slab and where the cracks are forming I can get a better idea. You can send them to [email protected] Regards Andy

Water would still be required to hydrate the cement and to give enough strength to bind the sand together.

@@SpeedScreedLimited How much water to an 8:1 ratio, please?

@@davidcottam7431 Nice to hear from you. There are a few factors that will change how much water you need. The snowball test is still the guideline. Enough water for placement and hydration. Please watch my video on water which will explain. kzbin.info/www/bejne/rKmZqKpsmdeKr5Y

@@SpeedScreedLimited Thanks, Andy. Makes perfect sense. Though I must remember not to get carried away and throw them at passing cars!!

@@davidcottam7431 Very true, might be tempting! Anything else you need, just let me know David.