Traditional construction uses nails and to lesser extent screws tie members together. However with time, wind and rain members move and twist which over time allows them to wriggle loser and loser.
We have had to question ourselves the best method to join all the parts together.
Just like the F-22 Stealth fighting jet, or Boeing planes or F1 racing cars, we are opting for adhesives which in the current era are unbelievably strong both in strength and sheer. The main question is whether we can find a glue strong enough to do all the adhesion or whether we need a combination of glue and mechanical fixings (screws).
The early design for our system had floors / ceilings attached to the side of a wall to allow for a wall to continue up to become a parapet in one panel. This is a good idea, but limits the stresses we can have on our floor systems which over the more recent calculations has really shown us how important they are. So moving forward we will always (in most cases) have the floor / ceiling sit on top of a wall like below:
As per usual, from a small design setback (not continuing the wall up to a parapet) a separate better idea comes about being a fully molded roof system (will create a separate blog about this - pretty exciting really).
So glue is now not as critical as it was going to be earlier in the week when it comes to sheer properties; still important, just less important...
So our next challenge is to investigate into what is one of the most important parts of the system - the glue. To find the right glue we are factoring in the following:
Time (can it stand the test of time, dirt, rain, general abuse of life over 50years).
ACS-A have found 2 types of epoxy resin that they feel is a good place to start testing. This adhesion method is very strong. However I have questioned the other points in the list above as they are more important to our system / goals than simple strength. So over the weekend I have found a few other alternatives which ACS-A will look at in the coming week. The main thing I found is a structural adhesive silicon.
Not your normal silicon you buy from Bunnings! This is very strong, can withstand more than 220deg of heat, is completely waterproof and has some elasticity.
Elasticity is important (in my view only at this stage) as when the join can have a small amount of movement (talking extremely small) the join is very reluctant to 'let go'. With very strong but very rigid joins, they will stick very well up until a point where it will completely 'let go'. This is my fear over 50 years, that these very strong and rigid adhesives may not stand the test of time.
This is our focus for this week. To work out what will be the best way to adhere our system together and whether we will need any mechanical fixings.