Cross-measure room...not matching yet, then?

[berne88]

I'm not getting it

I've put a screw in each corner as far in as I can, then I took masonry string, tightened it to make a cross, then quickly tied a string around everything, to have it straight against the walls.

Then I measured 280mm from the string along the walls, set screws, and then took thin string to make lines. But when I checked the measurements from the cross of the strings to the 280mm marks, it doesn't match... how can it not match?

All tips are welcome.

 

[MathiasS]

I don't understand the 280mm. What is wrong?

 

[Traume]

you should measure the screw 280 mm from the wall on the diagonal

 

[berne88]

I don't understand the 280mm. What doesn't add up?

When I measure from the middle, where both strings cross each other, out to the line which is 280mm, I get different measurements when comparing opposite sides.

280mm is where I'm supposed to lay the tiles for herringbone parquet.

 

[Traume]

As mentioned, the diagonal measurements should be equal when measuring, so if you measure from the 280 mark in the corner to the 280 mark diagonally across the room, then check against the other diagonal, if it doesn't match you need to adjust the 280 markings equally until the measurements are correct. For example, if the cross measurements differ by 50mm, you move the 280 marking out by 12.5mm at each end on the short measurement and 12.5mm in on the long measurement.

 

[berne88]

There you can see the corner, the pink string is the one I have measured in a criss-cross pattern with, the blue one is the 280mm lines.

I will have a straight square in the room, and then a middle line.

 

[Traume]

HaHa if the room is rectangular, your measurement method can never align accurately.
But if you take a tape measure and measure from the blue cross diagonally across the room, then measure the other diagonal, it will be correct.

 

[holmberg87]

Can't you start from a corner, angle off by 90 degrees, and for example use a laser or calculate? If you use all four corners, I think it will be difficult to measure to a rectangle with right angles.

 

[Traume]

If you want to place it as neutrally as possible in the room, do as I wrote.
If you just want to follow one wall, start from there and calculate as follows.
If we assume the room is L3MxB2m
length X 2 (3x2=6) + Width X2 (2x2=4) =10 then take the square root of 10 which is approx. 3.17m
The diagonal should be 3.17m for the angle to be 90 degrees.

 

[berne88]

If you want to place it as neutrally as possible in the room, do as I wrote. If you just want to follow a wall, then start from that and calculate as follows. If we assume the room is L3MxW2m Length X 2 (3x2=6) + Width X2 (2x2=4) =10 then take the square root of 10 which is about 3.17m The diagonal should be 3.17m for the angle to be 90 degrees

I can say this, math is really not for me.... What you write is pure Greek to me..... I wish I was much better at math than I am

 

[Traume]

what are the dimensions of the room?
for example, from your blue cross on the length and width of the room

 

[falkn]

You don't need to have 90-degree angles to lay herringbone. Measure your border and listband from the wall, don't forget the expansion gap of about 6 mm. Draw this on the subfloor and then mark a centerline in the room that you lay along. Test lay first from your line so you don't end up with very small pieces at the start of the listband.

 

[Farfalle]

I can say this, math is really not for me.... What you're writing is all Greek to me..... I wish I was much better at math than I am

What Traume was trying to explain is the Pythagorean theorem, i.e., how to calculate the length of the diagonal of a right triangle if you know the lengths of the other two sides (in your case, how long the sides of the room are). Unfortunately, the explanation was a bit misleading as it's the lengths squared and not "times two" that applies.

So if one side of the room is 3 meters and the other is 2 meters, the diagonal of the room would be as follows:

3*3+2*2= 13 -> the diagonal is "the square root of 13," which is about 3.605, or 3 meters and 60.5 cm.

 

[Traume]

HaHA saw that I made a thought slip should be 3x3 not 3x2

 

[Traume]

Follow falkn's instructions, then cut the frieze with a plunge saw and mill a new tongue.