Knit flat bottom up raglan sleeve help

[Shoopideedoop]

Oh wise knitters of mumsnet, I need your help! I may be overthinking but I am also not the most experienced knitter.

I'm knitting a sort of simple oversized cardigan. It is knit flat, from the bottom up...the back and 2 front sides (with decreases for raglan) and the 2 sleeves which are then all sewn together.
The back and front are complete and sewn together, they fit well, with holes ready for the sleeves.
The sleeves are first a few rows of ribbing, then an increase row, lots more rows to make them long enough and then the decreases for the raglan shape...

(K2, ssk, knit until 4 stitches left then k2tog, k2, purl the next row) Repeat until raglan/decrease measures 16cm (this took 24 rows) and then cast off remaining stitches.

Then sew up the sleeve (until decreases start). The decrease edges and the top row of cast off stitches are what I need to sew into the arm hole. Except...it is not quite long enough to fill the hole (need maybe 4cm more).

So, I could just make the decrease section a bit longer, but...more decrease rows = less cast off stitches on the top = no overall increase in edge for me to sew in?
Or, should I, after every 4 rows (so decrease row, purl row, decrease row, purl row) add in an extra knit (without decrease) and purl row? Or will this make a messy, jagged edge that won't look nice?
I would really appreciate some ideas/advice! ☺

I think that this is a tension problem (your tension over stitches could be correct but not over rows) but I am not sure of the best way to correct. However if you post this query on Ravelry.com. I think you will get some ideas. The forums have lots of really helpful knitters who seem able to answer almost any question.

I'll give that a go, thanks! ☺

First of all, are you sure it is too short? Check the picture to see if it looks like the shoulders are bulkier or gathered along the sleeve edge as it is possibly a question of easing the sleeve around the arm hole. Also, check the instructions for the order of sewing up in case you were meant to set the sleeves before joining the back and fronts (if so, don’t worry, it’s just a thought).

Then, I think you could do your extra row idea without creating a problem. It shouldn’t create a jagged edge in the finished sleeve because you will sew in the edges. When you decrease you sometimes end up with a sort of point at the decreased edge, and this disappears into the seam.

Often tension changes during a project for infrequent knitters (ie me but not my mother or grandmothers!). If you knitted the sleeves last, measure your rows on the sleeves to see how many extra rows you need to make 4 cm, then you can work out where to start/how many to add.

I’m trying to visualise it and I think you won’t create a problem with the overall sleeve length, as long as you don’t change anything below the first decrease row.

Did you get any good advice from Ravelry?

I agree with Gremlins that your extra row idea could work fine but 4cm is quite a difference. I would check that you haven't followed the instructions for the wrong size - eaily done with multi-sizes.
Also - you probably realise this but with raglan sleeves the top of the sleeve forms part of the neck edge. If you are trying to enclose it completely like a set in sleeve that will not work.

Yes good point @Yonderashgrove , you should certainly cast off the original number of stitches so that the neck comes out right 😃