Building an Extension #7 - Roof Build-up & 3 4 5 Rule 

3 - 4 - 5 otherwise known as Pythagoras' theorem

Love these videos. A refreshing change from the deluge of American videos. Keep em coming

Love your videos Roger , I learn all the time from them.

I'm in the trade and really appreciate the videos ,interesting to see other jobs.

Such talent, hard to believe this is not scripted and rehearsed many times. Not one unnecessary word, during lockdown and schooling from home you should be a teacher Sir!

I've been watching your channel for the last few months, I've learned alot through your knowledge, but your passion and inspiration is what really makes a difference. I'm just about to retire after 24 years Army service and am doing some very basic work on my house and it's helped alot. Thanks.

Your practical knowledge is never ending Roger!

Hello from California! I learned something... Great content, keep up the fantastic work.

Great video I like the way you explain construction methods. More like this needed - learnt something new.

Roger, Could I just say you don't have to look up the internet or use a table if you have the calculator that you may use to multiply, you need not do that if you are using an ordinary calculator that has the button that shows COS: short for cosine Just take the run that you spoke about say for example, punch in 2.4 for the run Then hit the divide button then Cos button then punch in 35 =2.9298 length of rafter, so shortened version looks like this 2.4 divide COS 35 degree = rafter length it probably reads more complicated than it really is (HONEST)

I luv an old school builder. Keep up the great work

More of this please! Mainly American videos on framing and roofing. Great to see some English videos 👌🏼

The old rafter would be 4" and the new ones 6" so the wallplate on the new bit must be lower .

Gret Roger. Always like you r videos mate. Funny though how you bamboozled us with the maths and tables, and then said, just put a piece of timber on the drop and mark it. LOl

Where do you supply your timber from? it seems to be really nice quality, great vids, thank you

Hi mate. Been in contact with Anthony at the Brick Brace company after seeing your other video putting the steels in. Very handy for us always changing corroded lintels and beams. Liked all your videos so far, have toyed with the idea of doing my own, just haven't found the time. I think people like your videos because you clearly explain what it is you are doing and connect with the viewers. Keep it up mate. Jerry

three, four, five. i love it, i've learn't something new and really useful.

Great explanation of whats involved

3-4-5 Bravo! You can't believe how helpful i'm finding these videos! Thank you for your efforts.

I’m a trial and error kind of guy, done lots of roofs and now I’m at the point where I can build a roof to a good standard. I’m doing a loft conversion (on a 30’s semi) at the mo and I’m fitting a new roof onto an old wall plate (from hip to gable) that is 60mm out of level and have to match the old tiles and fascia board (next door) into the new. Your method won’t work, as to match the new roof into the old and keep the eves (looking) straight at upper 1st floor window height I have no choice but to cut the roof pissed. Each rafter has to be cut individually. The new ridge is nice and level as is the new loft floor but the fascia board is pissed and the rafters have to be cut to suit. The tiles next next door are also 100mm out of line from fascia to ridge and the outer left hand wall has a 50mm bow in it....sleepless nights for me 😂 I’ll get there. Sorry to bang on, just needed a shoulder to cry on 😁. Good work though.

Learn so much from Roger- cheers buddy

3 4 5 right triangles rule!! I knew before about this particular "right" (90°) triangle where the legs are 3 & 4 and the hypotenuse (the long side) is 5, but I never knew that carpenters could use this trick to check if a corner was 90°. Pretty cool! Permit me to put in my own 2 cents: when you use the 3 4 5 method to check squareness, you will need to mark your end points very precisely since if you are predicting where, for example, a 9.144 meter run (30 feet) ends up, even if your 90° corner is off by only a quarter of a degree (0.25°), the other end of the 9.144 meter run will be off by 39.9 mm (1.57 inches).

If you like old time wisdom, here's how you can check the levelness of your project using a method that the builders of the Egyptian pyramid used - The Egyptians dug a trench the whole way around and also into the the pyramid foundation site and filled it with water which created a level reference. I know you don't want to dig a trench, so, first you get yourself a long garden hose and then stick two ~12" long clear plastic tubes on the ends of the hose (water tight) and then add black circumferential lines around the tubes at their centers. Next, you securely affix one end of the garden hose at one location on your build with the black line aligned to, for example, the top of a beam. Next, you affix the other end at any other spot with that end's black mark at, for example, the top of another beam. Then, you fill the garden hose with water (use a funnel) until the water is up to the mark on the first reference end (make sure the middle of the water's meniscus is at the mark, not the outer edges). Now, if you go over to the other end, you can tell how far off level that other location is by measuring the distance from the water level at that end to the black mark on that end. This trick works no mater how higgledy piggledy the center of hose is, as long as there is water in the whole hose and as long as the center bits of the hose are below either end and as long as you are not off-level by more than half a foot. You can check the level over as big a site as you want as long as your garden hose is long enough.

great info cheers - most thorough explanation of wall plate and ridge detail.

Your job is great. You love the winter weather but i hate it. It freezes my fingers and i can't press the button's of my total station. I used many kinds of glove's but still i can't find a suitable pair for me until now. I can't write down wearing gloves or even to open a blue print just for reference. And i can't even think about windy days.

Bloody good videos ! I’m learning so much! Thanks!

Explain down to a Tee. 🤔 Tea break.

Allways bed the wall plate , that's what ensures the load is evenly spread across the plate...

So useful, learn plenty.. 3.4.5 fantastic thanks

3-4-5, amazing! Really enjoying this series.

Easy way is get up to wall plate height and get a truss company in to do that ,Works out cheaper then getting a couple of Joiners in to do the roof

how long did the extension take to complete? great videos by the way.

Who ever told you that u will never need pythagoras Thereom lied.

Nice videos. I'm Tenneesse U.S. I just found your channel and I love it. I'm not a house builder but i familiar with U.S. construction. I didn't know in Britian you use brick walls as load bearing support walls. Houses here in the southern U.S. the brick is laid last, after windows doors, eaves soffit and fascia. It is strictly a veneer. You guys are great craftsman! Fun to watch.

Still probably better built than a new build estate

Top quality workmanship

Roger, me as a long time Carpenter and Joiner I have learned to Curse the bricklayer quietly as more often than not they are bigger than myself so i just have learned to get over what is thrown at me.

I prefer to go for the diagonal measurements for checking square on plates, more accurate over a larger distance.

fantastic explanations again love these videos

How's robin's new gaff coming along?

What are those plates sat on , are they on mortar or straight on the blocks , couldnt quite see

get a better tape mate that floppy things as good as my old bill

Is Jimmy Bullard a builder now!

Great stuff as always Roger! Thanks.

"You can't expect these buildings to be spot on" Describes every single house i have ever been in, even newer ones.

Roger the pice of timber over the last row of bricks is there any waterproof on the bottom of the timber ? I am not sure if this pice get wet.. Maybe it pulls out some water of the bricks ? Sorry for my English

found this video very informative thanks .

Nice. Another score for Roger 🤗

I always look forward to the next episode RB, very entertaining and informative at the same time.

Don't forget the wall restraint straps Roger :-)

Are those radio ear defenders Robin wears?

Fascinating

"Great work Well done"

Thanks many Roger

First time I've heard of 3 4 5 . Something I will use again and again

Just measure the rise ( top of ridge) and use your run ...a construction calculator will give you the pitch (degree) and diagonal ( rafter length) minus half the ridge thickness.....push the button again for hip or valley rafter. Always match ( dead heights) distance from top of plate to top of rafter , plumb with the outside of the plate. .....of course there’s much more ...like “drops” which is the bottom of soffit to the top of the plate to match up trim....and so on....

i fucking love shreddies ,not that frosted bullshit variant of it either