The subject of expansion

[Diamond Pool Finishers]

Lec 32 | 8.01 Physics I: Classical Mechanics, Fall 1999 - YouTubei find expansion a very interesting and much underestimated subject, we all should follow standards when fitting expansion joints in to our work ,but have you ever stopped and thought about it ? ! is this joint wide enough ? yes it must be the guy in the shop said this is what i must use , well he is just selling something off the shelf, we have flexible adhesive BUT how flexible is it ? every piece of material ie WOOD , METAL , PLASTIC ,GLASS anything will expand and contract all at different rates ,when BS standards were put together last ,what were we using? , now so many different layers of materials in for instance bathroom floors are the standards up to date ? ( probs-not ) for instance if scientists know the expansion rate's of all the different materials ,then we have values so why don't we know the values of all the materials we use in the tiling world , why are there not values written on bags of flexible adhesive ?? & modified renders/screeds ?? we all seem to think OK this sub straight /material/situation will expand but by how much,? how do we know the flexi-whatever is flex i enough ?

 

[White Room]

How many would understand these values Dave, I know I can put render on a wall and it will stay there because that is what I have always done.

Remember there temperature changes as well which are out of the companys equations for their adhesives.

 

[Diamond Pool Finishers]

How many would understand these values Dave, I know I can put render on a wall and it will stay there because that is what I have always done.

Remember there temperature changes as well which are out of the companys equations for their adhesives.

well it could be put into layman's terms,and directed at the materials we use in tiling only.
expansion is not just caused by temperature it can be caused by swelling due to absorbing moisture ,movement, in structures. Thermal Expansion: Table of Coefficient of Thermal Expansion of Building Materials - linear expansion of glass, metal, wood, masonry & plastic in response to temperature changes < just found this so there we are ,perhaps we should all be taking these figures in to consideration when working out what we need to do to cover ourselves .........

 

[Ajax123]

A lack of understanding of the values is not an excuse for ignoring the need for joints as so many flooring contractors do.

In my opinion tilers, screeders and concrete finishers should make it thier business to understand that joints are needed, why they are needed and at what points they are needed along with the sizes for said joints. If they are armed with that information then they can effectively design and answer questions when a customer says they don't want joints in a tiled floor for example.

It is not a case of understanding the nature of the universe and quantum physics.

Good thread DPF

 

[Diamond Pool Finishers]

i agree Alan , we could do with some more input from adhesive manufactures to answer a few questions,that is what i 'am saying in a roundabout way Alan we should have the knowledge at our fingertips just for piece of mind ,as i think it is the job of they designer/architect to check the engineering side that it all works without failing, but you see failures all around when you go to the shops's for instance rendering on houses cracking, brickwork walls cracking ,just look around when you leave your house it's everywhere ,and it's all poor work.....

 

[Ajax123]

I think to expect general tilers to have the information on the tips of their tongues possibly unreasonable although it would be nice. A few basic facts yes e.g. Maximum bay sizes for different tile types, stone, porcs etc, minimum spacer sizes for different tile formats, minimum and maximum sizes for expansion gaps I would expect these as a norm. More technical stuff like the rate of expansion of a sand cement screed or a gyvlon screed or the amount of deflection or expansion a tile adhesive will take before failing could be in an information portfolio of some sort. Hmmmm.... Perhaps there is an untapped market for this information....... I hereby claim the idea as mine seriously though if there were a guide to this sort of information how useful would it be.

I am utterly flabbergasted sometimes at the lack of knowledge out there
amongst so called professionals in almost every aspect of the construction trade. Forums like this are a great way to disseminate information but even here sometimes I am at a loss for words at some of the things that are said. Mind you not had a really bad thread on here for a while so maybe the presence of people who do know what they are talking about is having an effect.

 

[Diamond Pool Finishers]

( I am utterly flabbergasted sometimes at the lack of knowledge out there
amongst so called professionals in almost every aspect of the construction trade.)

Me to !!!and also in my specialist area of swimming pools ,some company don't have a clue, yet they land prestigious jobs , but putting a few posts -up like this to me is what forums are about all of us having a good chat about stuff that will enlighten us all, .........this can only be good . that is why i like to read your stuff on gyvlon screed's its all knowledge and some of it is transferable to other areas .......

 

[charlie1]

To understand the expansion rate of a particular material we would need all the factors that contribute to the expansion rate I can think of material, temperature, gravity and moisture but there may be more, there are so many different combinations that would affect it to give different expansion rates based on xyz so we just work to guide lines on hope it works

 

[Ajax123]

To understand the expansion rate of a particular material we would need all the factors that contribute to the expansion rate I can think of material, temperature, gravity and moisture but there may be more, there are so many different combinations that would affect it to give different expansion rates based on xyz so we just work to guide lines on hope it works

This is not as complicated as it sounds. All materials have a co efficient of expansion. Taking moisture out of the equation as construction materials that are designed to be used in moist conditions eg tiles, screeds etc should not be prone to swelling as a result of moisture. Gravity has nothing to do with it so most movement is to do with thermal activity. The differential levels of thermal expansion/contraction in combinations of materials should be considered by designers and manufacturers and these principals are one of the reasons that uncoupling membranes are useful.

Generally speaking most construction materials co efficients of expansion are listed in various manuals. I know the tilng association has a list of rates of expansion of most tilin materials, screeds and concretes.

Most materials manufacturers will have published data on the coefficient of expansion for their materials.

Thecalculation is also relatively simple

If the co efficient of expansion of a material used in a swimming pool for example is 1mm per m Kelvin you simply look at the range of temperatures a material will be subjected to e.g. A swimming pool might operate in a range from 0degrees up to 30degrees (I don't lke the water too warm personally) so if the coefficient is 1mm per degree c then the amount of expansion from the coldest point to the warmest point is 1x30 = 30mm per linear meter Obviously the sum is for example onl as most materials are oohing like as expansive as 1mm per degree.

Gvyvlon is relatively low at just 0.012 therefore if gyvlon were used in this swimming pool firstly I would I would explain that the physical expansion would be 0.012x30 = 0.36mm per linear meter........... I would then say dig it out as Gyvlon is not suitable for use in a swimming pool....... Simples

 

[Diamond Pool Finishers]

HA Ha ALAN your a lad reading that i got exited when you mentioned swimming pool expansion, then you said about gyvlon in a pool ,WHAT ! then you said digit out LOL,
No it is easy to work out the expansion rates for the materials we use a lot in this trade, but why do you think the manufactures don't put them on the outside of there bags? i think it might have something to do with ,them not wanting to have the finger pointed /liability ,if there was a problem and peeps wanted answers ??