Solid Hardwood, Engineered and Laminate Flooring - Diagonal Install - Laminate Floor

Hi folks, :)
I'm an experienced DIY enthusiast, but have never installed laminate floor before, I've been looking for information about diagonal install, but it’s hard to find. :wall:
My doubts are about the main differences and difficulties I may find on the diagonal install, but any information is helpful of course. I'm installing on a small appartment, 2 bedrooms (11sqm/99sqft each), and a living room with a small corridor (28sqm/252sqft), my old floor is long wood planks over an air box, it will be straightened to be flat.
About the preparation, is a anti-damp screen necessary? And about the first lines, how should I proceed? Can I make the whole house without separation between the rooms? How it works when it passes thru doors? Should the floor go under the whole frame? Or should I leave some dilatation space and fill it with rubber or something?

My apartment (http://www.elements.st/main.alb/pessoal.alb/familia.alb/casa.alb/01_planta.jpg)
Many tanks,
Fabio. :coffee:

Fabio,
I am doing a diagonal install at my daughter's house in a couple of weeks. I agree- not much out there on diagonal installs. Beyond the standard info- what I've gleaned so far is that you have to watch total length/width as each manufacturer has a max length/width. Diagonal may make your length beyond the max. A 12x 20 room, for instance, has a 23 1/2 diagonal. Also, you definitely want a T break transition between rooms, to account for expansion differences. Yes, undercut the jams.
Good luck - and if you do yours first post back to let us know what you learned - and I'll do the same.

Hey Bob!
I'm glad you answered, but I didn’t completely understood what you mean with "T break transition", or maybe I just don’t want to :p ... The maximum length isn't a real problem as I have a tiny European apartment, and I read somewhere that for that area(50sqmt) I could make the rooms with no separations at all.
Sure I will share all that I may learn in this process, I may start executing on the next weekend and we will see. I've talked to a professional installer, and he told me that the waste is not a big deal since you don’t try to match the joints, he told me to cut the doorframes also, and the rest should be linear... I haven’t made my mind about using a screen before the underfloor yet, I let you now... :coffee:

Thanks for caring... And excuse my poor English.
Fábio.

Fabio, when installing laminate you have to have a breal between rooms. This is since the laminate may expand/contract differently in different rooms. So the laminate is installed with a gap in each door way. The "T" I am referring to is supplied by the manufacturer (ordered seperately). It's like a mini door sill. The leg of the T sits vertical in the gap between the laminates, and the top of the T covers the gap.

I got It, It has a different name here in Portugal, anyway... I've read somewhere that I dont need it for my small home, I read that its ok if under 100sqmt... :confused:
Should I worry about that ??? I understand and agree that some rooms may be warmer or with more humidity than others during the day, but they are just small rooms, should I use T breaks between them???
You can see my home plan at my first post if needed...

Thanks in advance...
Fábio. :D

Ps: I've already leveled the floor's greatest irregularities, next saturday I start placing the boards... :coffee:

We did the majority of the diagonal install over the weekend, (in addition to two other rooms that were not on diagonal) The major problem we had was pulling the last board in tight at the end to end joints. Since the edge is diagonal it was hard to pull straight to get the ends to pull tight. the long joints were no problem- same as for a straight install. Took some wedging, some pry bar and some finessing.
Also a little fussy figuring the angles around some of the door jams.
Took almost twice as long to do as the straight rooms. But it's in and looks great.
I've done may installs of regular hardwood flooring, including diagonals, and IMHO the laminate was definitely harder to do on a diagonal than regular hardwood.