Mortar question

[cannyfradock]

Tscarborough

I will try to answer all your questions the best can. As regards the addition of soap into a mortar mix :- Here in the 60's liquid soap was apparently widely used within the building industry for an ad-mix with mortars and concrete. It was only found that this was the case in the 1980's when, many buildings were demolished because of the costic/amonia content in a water mix was above the neutral 5ph(I think) value of water. Anything above or below i.e. below +5ph...acid or above +5ph.....soap would rot the steel re-bar.

Regarding plasticiser....this can come in 5 litre tubs or in 1 litre bottles of concentrate. Each plasticiser is mixed according to manufactures instructions to the correct quantity of water by volume.

You can easily put me down regarding the exact compound of a particular cement as this is not my job. On site here there are only normally only 2 types of cement used. Occainsionally fondu cement, but normally OP cement (ordinary Portland) which has a patent and can only ever differ in colour and not in content.

It depends on your role on site what you have to control. As I live in Wales most of the properties are built out of stone and uses a particular mix involving dredged sand. Across the bridge into England and in particular "Bath" the standards are different the mix is different and pit sand must be used.

Perhaps you are higher up the management level than I am. I am a foreman/bricklayer with a certain role to play within a company. Above me there is a quantity surveyor (which I work the calculations out for him anyway) a projects manager and "The Boss". I apologise if I can't answer your questions on "properties" of a particular cement, but I have enough to do with all the different types of mixes here, most all involving OP cement.

On the other hand fire-cement and fire-clay......please enlighten me

I hope I have answered your questions in a way that you understand, as the last thing in the world that I want is a dispute with a FB member.

Terry (C.F)

[Tscarborough]

Re: Mortar question

Sir, I am not and would never question the wisdom of a mechanic. Your skill is of the trade and the trowel, and I have nothing but respect for you.

I am not management or engineering, but that level that has to assuage the expectations of those two and the man in the field with the technical data and materials required to allow for quality, workablity, and profitable masonry construction.

Regardless of how the cat is skinned or where in the world it takes place, the underlying principles are the same.

[cannyfradock]

Re: Mortar question

Indeed Sir, same horse different jockey. I don't perport to be anything more than what I am.....a qualified "brikie" playing my role within a well organised team. My role involves many complications within a complex spectre of working with stone, brick and occasionaly cob. It depends what the ground consists of in the area which I am working in, as to what mix to use to build with stone, brick or working on a cob built thatched property. To say that I know the properties of OP cement for ex. would be a lie. In France it is another story again, where lime is used more in renovations to stone property especially when you have to match the existing property, where the sand is again defined by region, of which there are many types....Loire, Lonne etc.

There are many things to learn in the building trade within counties and country's in Europe and anybody who knows everything is a liar !!! In my opinion you must know everything within your field to be able to carry out your role as part of a team. I have worked in the UK as a "brikie", and worked as part of a stonemasonry team in France and in Berlin on the "Potsdammer Platz" but I have always worked in my capacity as a builder and never tried to take on anything beyond my capabilities. So far I have never had any comebacks on the quality of my workmanship

If you want to talk technicalities you could probably tie me up in circles. Or if the knife was deep inside you could easily start twisting it. I always work within my capabilities of what I know and it does'nt involve knowing the composition of OP cement.

Now then........fire-cement and fire-clay.....enlighten me

Best Regards....Terry (C.F)

[Tscarborough]

Re: Mortar question

Salute!

The internet is wide open and anonymous. That is why I use my real name, give my location, and answer any personal inquiries. I belong to several DIY and contractor boards, and offer my best practice answer to specific questions that I have knowledge of. Too often I see if not incorrect, at least inappropriate answers to general questions. 4 parts sand to 1 part portland cement with a squirt of soap is the wrong answer anywhere for any application, and that is what I responded to. Certainly it may work, and it may have worked for you (royal You) for the last 30 years, but it is not best practice nor is it supported by any testing and standards organization. Do not forget that for thousands of years, conventional wisdom saw no problem with dumping raw sewage into the source of potable water.

As to mortar for fireplaces and ovens, I am learning as much as I know, and can only offer advice on properties of ingredients and proportions. Trust me, I know a lot less than I think I know, but I am not afraid to admit that fact.

[cannyfradock]

Re: Mortar question

I have tried to be open and honest and I can't see where this is leading to.

Carry on putting me down if that's what you want to do.

Regards Terry (C.F)

[Tscarborough]

Re: Mortar question

Sir, I am not putting you down. I have nothing but respect for you. The internet is an imperfect medium for discussion, but please forgive me if it seems that I am disrespecting you.

[RTflorida]

Re: Mortar question

O. K. guys, I don't have a dog in this fight (you both know a helluva lot more about masonry than I), but I DO know what has happened here and am choosing to be the referee. I have been on both sides far too many times myself, on this same forum, with names you will both recognize.

Many of us think highly of our opinions and our levels of expertise. None of us are always right and most can admit it. The problem is the way we express ourselves on these damn blogs, forums, message boards, etc. The written word seldom, if ever, comes out the same way as it would in conversation. Personally, I come accross far too opinionated and confrontational than I would in any actual conversation...I/we just go too far trying to convey our message in writing with the same passion that I/we would convey in a spoken conversation.

Lets all step back, brush ourselves off, agree to disagree, have a group hug, and walk away mumbling to ourselves how "no one understands me, I'm too smart for my own good"

Have a good day guys.

RT

[david s]

Re: Mortar question

4 parts sand, 1part portland and a squirt of dishwashing detergent is a simple recipe. If you want to use a plasticiser then a one litre bottle must be diluted and then tis diluted amount is added in very small quantities. For a small job you will only need the tiniest amount. One bottle of plasticiser would last you a lifetime. Detergent is a suitable alternative plasticiser for the DIYer. A plasticiser will also make your mix more fluid allowing the use of less water in a concrete mix. Too much water in concrete is a major cause of weakness.

[cannyfradock]

Re: Mortar question

Again,..apologies on my behalf. On the other hand, I am up for ridicule as far as my oven is concerned.

We had a similar severe winter as East coast America had over the xmas period with long lasting snow and ice. I did'nt even have the common sense to throw a tarp over the oven, so needless to say the frost and ice penetrated deep into the dome. After the thaw I started what was going to be a gentle fire in the wood-oven to draw the moisture out. I managed to aquire many 8"x2" offcuts from roof trusses. I got carried away with the amount of wood being burned and ended up with a glowing inferno (photo's attached). After a short while the inevitable happened.....PLATCH.......too much heat, too soon and the dreaded cracks started to appear. Stood about 2 feed away from the entrance and tried to look inside for cracking, and my fringe caught alight and my eyelashes stuck together.

I built the wood-oven, about the same time as I started using the internet. All I had as a plan was a finished picture of a wood-oven to use as a guide. It was only after I finished the wood-oven that I came across, and joined the FB forum. After a short while of reading the posts here, I realised there were many things which were not correct with the build.Things like the height of the arch to the height to the height of internal measurement of the dome was less than 63% plus insulation issues.

I also found great difficulties in sourcing refractory suppliers here in the UK, which I am in the process of making it easier for people in the UK to find a refractory supplier in their part of the country.( Have compiled lists for anyone to access).

So...lack of experience in a particular subject and a large dose of stupidity have left me with a rebuild on my hands. Now with the knowledge learned over the last 6 months and a new source of refractory suppliers I am looking forward to the re-build.

Nobody's perfect.......especially me !!!

Hope by sharing this with you, it has made up for last silly posts here and on Kebwi's thread.

Best Regards to ALL FB members.........Terry.

p.s Re;- username......The first time I tried to register on a forum, I tried Terry Lyons but it was not avalable. Also tried T.Lyons, TJ Lyons, Tel Boy and nothing was available unless it had a lot of numbers after the name. I have already spent a little time in a place where numbers are compulsory after your name and I did'nt want to be reminded of that time....so chose cannyfradock.

p.p.s I must try and make these posts shorter.

[kebwi]

Re: Mortar question

Sorry about all this. I realize my combination of naivete and compulsive curiosity is fodder for all manner of discussion and disagreement. Didn't mean to start something up.

As I've always stated, I tremendously appreciate the input of everyone here since I took this project up having done little more than jigsawed a bit in the past. I'm a computer guy who merely like the "idea" of a shop but doesn't know squat and admits it.

I literally couldn't have built this oven without you guys. The Pompeii directions, printed out and stapled together, would not have been sufficient at my level of incompetence. The forum has been indispensable. Thank you to everyone who entertains my often pedantic questions.

Cheers!

[Tscarborough]

Re: Mortar question

OK, I finally found a copy of the standards for Britain (and Europe). It is basically identical to the US standard, although the way it charts it shows where the discrepancy creeps in.

Here, the formula is given as, "parts of sand by volume of all cementious materials". That includes lime. In your code it is not stated but assumed that the lime is a cementious material.

For example to make a US Type S or UK Type ii, we would both use 1 part portland cement, 1/2 part lime and 4-4.5 parts sand (2-1/4-3 by volume of all cementious materials).

Here are the two charts, US first, then British:

[kebwi]

Re: Mortar question

So, just to be curious (tolerate me)...

...what are the masonal implications of too little sand? What is the property of 4:1:1? I mean, how does it act differently from 5-6:1:1 as a material?

I ask because those tables are clear that 4:1:1 is below the prescribed minimum of 2.25 sand to sum of portland/lime.

Juuuuust curious.

[Tscarborough]

Re: Mortar question

No, they are almost identical just stated differently. Example:

United States Type S:

94# portland (1 cuft)
25# Lime (1/2 cuft)
3.38-4.5 cu.ft. Sand

British Type ii:

94# portland (1 cuft)
25# Lime (1/2 cuft)
4-4.5 cu.ft. Sand

[Tscarborough]

Re: Mortar question

To answer the question of why too much sand is not desirable, if there is not enough cement paste to thoroughly coat each particle of aggregate and fill the spaces between them, then the mortar will be weak in every respect that matters: Bond, flexural, and compressive, in that order. A prefect example of this is perlcrete. There is generally enough paste to coat the aggregate, but not enough to fill the spaces, giving an 1-8 mix adequate compressive strength, minimal flexural, and modest bond strength.

The latitude as to volume of sand in the standards is to allow the on site mason to adjust the amount based on the characteristics of the sand, the weather, the type of units laid and even the preference of the masons.

[kebwi]

Re: Mortar question

But my question was about having too little sand. 4:1:1 (or 2:1 sand/portland-lime) is below the 2.25 sand/portland-lime minimum specified in those tables. What happens if there is too little sand?

It's too late and it doesn't really matter since I just wanted to parge the rough surface and tie the loose aggregate together in prep for the SBC; it wasn't even suggested that I had to do this at all, so I don't think it matters...I'm just curious what too little sand does.

Thanks though for the advice on too much sand. Now I know. That makes a lot of sense.