Some Progress on the Sash Window Plans

My Appologies if you're waiting for progress on the plans for the sash windows. I've been distracted yet again, slowing me down but now I'm back on to it.

I've just completed a short analysis of the historical influences on the design of sash windows. Its the kind of background that helps shape some of the detail decisions I've had to make.

If you're interested to see where I'm coming from have a look here.

Feel free to leave me comments, knowing folks are interested helps me focus.

And, if you're up to speed with all this tinterweb stuff, the more who are keen, the more pressure on me to get cracking.




or share it from the web page

Cheers, Andy

Beginners Guide to Buying and Preparing Timber

In answer to one of the questions I've been asked, here's a Guide to buying Timber and preparing it for woodworking, carpentry and joinery.

It's written for a beginner like I was but it covers everthing that confused me at the time.

What's redwood U/S?
How to buy the right wood for the job?
How long do I acclimatise it for?

If you're starting out on a project like making your own windows it could well be worth reading.

How to, Beginners Guide to Buying and Preparing Timber

Hope its useful.

Box Sliding Sash Window Plans and Construction details

The first of my box sliding sash windows has now been installed for 10 months. It's still looking good and functioning well. The seals are keeping it draught proofed, there are no signs of any joint movement or wear and the double glazed units are performing as they should.

The only slight problem has been a sash cord stretching so one of the weight touches the bottom of box. I just need to move the knot up a bit.

Details and Construction of DG Timber Box Sliding Sash Window plans to Download?

It's now on my list to build the rest. Before I do, I will review the construction details and amend the plans if I can think of any better ways to do things. I'll write up and draw all the construction details, including measurements and installation. I'll also detail the manufacturing using basic workshop tools.

I plan to make all the details available as an ebook, available for a small charge. If you are interested please leave a comment to give me the motivation to crack on.

The sums seem to add up if you have the knowledge, skills and time. A bespoke bought window would cost around £1000 each and a home made window around £300. I've justified equipping my workshop/garage with part of the savings I'll be making. If I could have bought the plans a year ago I would have.

Let me know what you think.

Sash Weight pocket cutting

I've just been having a conversation on a forum about the best way to cut out the pockets for the weights. A specialist chisel was mentioned but most folks make saw cut. I ground down an old chisel and did a quick test.

Here's the result..

I'll try a slightly thinner blade and witha bit of practice it will be real time saver.

The problem I originally had can be seen here http://slidingsash.blogspot.com/2008/11/big-mistake.html

Window ONE Fitted and Working well

So the first window is fitted and working nicely. A few glitches and mistakes along the way, all part of the learning process. I'm chuffed with the result and so is Wendy.

Apart from top of the outside lining being too close to the brick arch. I think the proportion work well.

Inside it looks great and the double glazing doesn't distract at all.

I'll be re-working some of the design details with the benefit of hindsight. I'll also be monitoring the performance of this one for few months to see if there s anything else that can be tweaked.

My intention is then to detail the design and plans fully. Check everything by building the others. Then if all goes well making the plans available to purchase as an e-book or what ever they are called.

If anyone is interested email me or leave a comment any feedback will be gratefully received.

Fitting the sashes

I was glad I had practiced this as time was running out, it was getting colder and I just heard the weather forecast for up to 60 mph winds and heavy rain.

The cords feed over the pulleys and then the top sash is lifted so the weight can be attached.

The Lead weights first as they have a hole running all the way through then the iron weight tied on so so it just clears the bottom of the box.

The parting bead can then be driven in. I had pre-painted these and it was a good tight fit. May be too tight if I ever have to remove them.

The bottom sash goes in exactly like the top sash. Just in time as the rain started coming down.

Next day I fitted the pocket covers and Staff beads. Then another few days latter I finish it off with some architrave.

Fitting the New Frame

The frame eventually jiggled in quite nicely.

To lift the frame up from the stone cill I fitted a piece of squashed copper pipe under it. This went to about 35mm of the front edge. Just behind the drip groove. I sealed it with silicone later on. The idea behind this came after seeing Zinc strips under old window allowing the timber window to move with expansion and contraction whilst maintaining a seal upstand on the stone cill.

The whole frame is held in with four screws fitted at angles through the each corner into the brick work.

Taking the old window out

With a full day allocated for the job and assistance from Dave on hand we went past the point of no return and ripped the old window out.

Leaving us with the reveal looking like this.

After about an hour chiseling the brick work to get rid of the high spots the frame would just squeeze in.

Trimming it down

It was going to be tight fit. To give me an extra 6mm on the width I took the cover off one of the weight boxes, planed the rebate off and fitted some breathable membrane (roofing felt) on instead.

The top needed trimming as well. It's designed to allow for a bit trimming but I ended up having to trim more than I'd planned for.

Then It Went HORRIBLY WRONG

I nearly cried after I just checked the size of the old window to see how much plaster I'd have to take off.


The new window was too small, how can that be? what went wrong? How could I possibly recover from this.


I tracked the problem to the spreadsheet I had done to work out the dimensions. I found I had subtracted the size of the outer lining lining lip instead of adding it, resulting in the window being 80mm too narrow and 40m too short. OH S*#T.





After I'd calmed down I checked the other window sizes and Lady Luck came to visit. It should fit in one of the other rooms. A tight fit and a little too high but workable. Phew!

I did a little investigating with a crow bar to get the exact sizes of the brick work.

Getting ready to install

With the new lead weights collected I was ready for installation - Almost.

The Lead bought in one meter lengths need cutting down to the right size. The circular saw cuts it nicely. I also cleaned up and painted another 4 iron weights.

The weights dividers fitted in...

And the back of the weight boxes fitted. Made from 6mm ply.

I then did a trial fitting of one sash to make sure the weight would fit and to practice the procedure. To do this I fitted the cords using 25mm no.6 screws, 4 off on each cord.

With everything ready it was time to start ripping out the old window.

Finished Painting

It's taken me near enough a week to finish painting the sashes. I can only do one side at a time, it takes at least 24 hrs to dry and its had an additional 3 coats. I'm now happy with the finish.

I'm not certain about the putty used to fill the screw holes, it had skinned over but was still soft underneath. As a result sanding it flat wasn't very practical. However I got them fairly flat and it's something I can redo after the window is fitted.

When the lead arrives, I'll be ready to fit it. It's going to be tight getting it done before Christmas!

Weight built up - slight problem

Dam - worth a try on to plan B



I cleaned up eight of the cast iron weights and gave them a coat of hammerite. After much thinking about ways of connecting them, articulated so I could feed them in pairs into the pockets, I came up with this solution.

A length of stainless steel cable loops through the hole in the top weight down to the second weight. Both ends are clamped using a 12mm bolt with 2 holes drilled through, a washer and nut.

I had to keep the total length, after re-measuring, within 750mm to get full movement of the sashes. I just managed this, but realised I'd have to be really accurate tying it on to the sash cord.

I had calculated the weight of the sashes and set about adding squashed lead pipe to make up the weight. Easy enough to wind around but it took ages to mange to solder tack the spiral together. It was a cold night and iron took the heat away.

Disaster - I checked actual weight of the sashes using bathroom scales and I was short by 2kg on the made-up weights. More procrastination, I couldn't add enough extra weight without either increasing the width, or adding to the length. So it was back to the calculator and Plan B.

I'll use one cast iron weight and one proper (bought) lead weight. So not a total catastrophe as using the iron will reduce the lead I need to buy by half. I also think the ones I've made up will suit one of the slightly narrower window.

I've now ordered the lead and will be picking it up next week.

Shiny bits-hardware , note on paint

After another coat, Its not as glossy as the previous. I'm wondering if I laid it on too thick, I'll make sure I go really thin on the sashes and see what difference it makes.

But it's good enough, especially as the inside parts will have a final coat after its all fitted.

To free up some space in the front room, with Christmas coming and trees going up, I fitted the pulleys. A good tap in fit. mmm shiny bits. Now its residing on the landing.



I've now got the sashes to paint and weight to sort out. Maybe I'll finish for Christmas?

Glazing the sashes

This is the interface between old joinery with up to date fenstration (glazing)

I picked up the Double Glazed, after a slight delay - I've ended up with two toughened units for the price of one. On close inspection the two panes of glass aren't perfectly aligned and the edge spacer, being a flexible foam, isn't perfectly straight. I don't know what tolerances are usual so I'm not going to gripe about it. The edges are sealed with a hot melt black, slightly tacky stuff. This is uneven on the edges of the glass and compound the slight miss alignment of the two pieces. For the other windows I'll ask if they will pay a little more attention to this.

The sealed units fit in the sashes, resting on 5mm deep bridge packers to maintain ventilation around all the edges This should prevent any moisture from attacking the edge sealant.

The packers I bought are 24mm, the rebate is 28mm so I cut little tabs in edges so the packers will sit in the middle.

I'd ordered the units 10mm under the sash rebate sizes. The sashes are about +/- 0.5mm and the glazing (due to the misalignment and edge seal build up) are about up to + 1.5. So I had to sand down some of the packers to get neat tight fit without distorting the timber of the sash.

Next the adhesive backed EPDM seals are fitted.

The bottom seals extend horizontally and the side pieces end butt up to them.

After tinkering with all packers I was happy to screw the beading/clamp on.

Note: I had counter bored the holes a few mm to much, the head sank a bit more than I expected.

I'm generally happy with the result. The glass held firmly, the seals are well compressed, it looks neat and nothing like a plastic DG window.

The only thing that bugs me is all the screw holes that need filling. It does mean I can dissemble the sashes if or when the units eventually fail. However I keep pondering if there could be a more elegant solution, possibly using the mechanical strength of the actual units ????

Last bit of glazing is to put a bead of silicone around. I choose only to do the outside, I'll wait and see if there is any need to do the inside. In the spirit of experimentation I did one with no masking, point proved, I can't gun and tool neatly without have to scrape loads off the glass and frame. The other one I spent 5 mins masking up and did a much neater job.

USE : Low modulus - Natural cure , this is flexible, and doesn't have the solvents that react badly with Sealed units and glass coatings.

The stuff I found is labeled as a frame sealant, not glazing sealant.

This pic shows the silicone with a layer of paint on it. Can also see the silicone bead doesn't fill the flat on top of the bevel.

Note: Consider adjusting the design bevel. Reducing the flat and the over-all sash thickness.

Also prior to painting I've filled the screw hole with linseed putty. I'm not sure about this but it's reccomended by the paint manufacturer so I'm trying it.

Weights - cheap option

I was ready to order the lead but had a quick look on ebay. I found an auction on with 24 hrs to go for an assortment of 10 cast iron weights, for pick up close to home. So I put a bid in and won for £2.50 - what a bargin. He had a load more when I went to collect so bought the lot for £20.

It will not be a perfect solution as the weights are oly about the right size for single glazing. I've worked out that if the weights are less than 800mm I'll get full movement of the sashes. So I can hang one under another and wrap some scrap lead pipe around them to get enough mass.

If this works out I'll have saved about £300.

Linseed Oil painting

The main drawback with linseed oil paints seems to be the drying time required. 24 hours at 20 -25 degrees centigrade. With the weather as it is this means I've abandened the workshop and taken over the front room.

The first coat is of raw linseed oil, applied hot, 60deg. I decanted some in to tin and warmed it with a hot air gun, it only takes a couple of mins to get it up to temperature. It's brushed in vigerously in a thin coat. I ran over it with the hot air gun as well to aid it soaking in.

It's lovely stuff to use, pleasent smell and doesn't matter if you get it on your hands. The only problem was, due to slippy hands I dropped the tin. Small panic, but most landed on the news paper.

It took three days to dry, at and average temperature of 18 degrees. So a can't get away with not turning the central heating on, we normally rely solely on the wood burner in the dinning room.

Next step - Shellac on the glazing rebates and knots. Easy, Quick job.

The first coat of paint is worked in well and thin as with the raw oil

This dried within 36 hours after I closed the door and put the heating on.

The first coat covers well and dried to matt finish

Untill I've got the glass fitted I can't do anything else with the sashes but I can with the frame.

A light sanding of the frame and filling screw holes with puty, followed by another coat. A patchy gloss is developing,

I think the third coat will give a lovely finish.

Glazing Ordered

I've been and ordered the sealed units today from a local company "Pro-Glass Glazing Services"
These will be with foam type warm edge spacer and hot melt sealed, one toughened one standard, with pilkington K.

Total price now with only 15% VAT - £114.12

The final straight

With all the wood working done all I've got to do know is:

1. One coat of raw linseed oil
2. Shellac on the glazing rebates
3. Order, and fit the glazing
4. Silicon on top of the seals?
5. Paint first coat
6. Paint second coat
7. Order and collect lead or steel
8. Take out the old window
9. Fit the new one, that should be fun.
10. Paint third coat
11. Plaster up
12. Architrave
13. Decorate.
14. Have a beer or two to celebrate
15. Start on the others

Now there's a plan........

Last bits for the frame

All that remains is to cut the parting beads and staff beads.

I cut out a radius on the bottom of parting beads to ensure water wont lodge behind them.

The staff beads are mitered. As my compound miter saw, compounds and miters as it likes I set the cross slide on the router at 45 and trimmed the ends to get them bang on.