Onoff Posted June 24, 2019 Share Posted June 24, 2019 About to slap a 20kg tin of Chromapol, grey roof repair compound over my "on it's last legs" dormer roof. Area is nom 24' x 8'. Tin says I should clean with Cromar Alpha Chem Moss and Mould remover. I have none! Can I use some bleach in water? Link to comment Share on other sites More sharing options...
scottishjohn Posted June 25, 2019 Share Posted June 25, 2019 do you have moss on roof now ? if you don,t then it is obviously too hot or dry for it to grow --so --no i would not bother Link to comment Share on other sites More sharing options...
Onoff Posted June 25, 2019 Author Share Posted June 25, 2019 1 hour ago, scottishjohn said: do you have moss on roof now ? if you don,t then it is obviously too hot or dry for it to grow --so --no i would not bother Yes, there is some greenery because the fall is so slight. This is during a previous repair: It's not a good detail imo generally. From looking inside that 3 tile ridge piece that I can access from either hip end the whole roof, about 24'x24' was first covered in 3/4" ply on fittings sloping from the centre. The ply was covered in a layer of sanded, (not green mineral), felt. THEN, the ridge was built by nailing 4"x2" apex pieces against the ridge board. Subsequent layers of felt were laid on the flat bits and up and over the ridge. That original felt failed. Subsequent re felting has been put over the top of the old (not guilty). The tiles just come down over this newer felt. I've been putting this off for a few years now. I'd like to extend the eaves a bit to overhang more. Maybe even do a hidden gutter detail and fibreglass the roof like @Barney12 did which looks superb. I was half thinking to do away with that central ridge piece completely to give one big roof area. Or maybe making provision for, an albeit flat, PV install. Maybe with a central access hatch? This will likely be my next project! Link to comment Share on other sites More sharing options...
Barney12 Posted June 25, 2019 Share Posted June 25, 2019 (edited) I've used Chromopal on a big flat roof a few times. I've never used the cleaner. I would scrub with a degreaser, not bleach. Ensure its well rinsed and dry before applying the Chromopal. Truckwash is your friend, cheap and effective: https://www.amazon.co.uk/CAUSTIC-TRAFFIC-REMOVER-TRUCK-include/dp/B071FYMTL9 Edit: That link is expensive. Any decent autoparts factors should sell you a 5ltr container for £20-30 max. Edited June 25, 2019 by Barney12 1 Link to comment Share on other sites More sharing options...
Onoff Posted June 25, 2019 Author Share Posted June 25, 2019 (edited) 57 minutes ago, Barney12 said: I've used Chromopal on a big flat roof a few times. I've never used the cleaner. I would scrub with a degreaser, not bleach. Ensure its well rinsed and dry before applying the Chromopal. Truckwash is your friend, cheap and effective: https://www.amazon.co.uk/CAUSTIC-TRAFFIC-REMOVER-TRUCK-include/dp/B071FYMTL9 Edit: That link is expensive. Any decent autoparts factors should sell you a 5ltr container for £20-30 max. Cheers. Seems a bit counter to the issue to scrub then hose off an already leaking roof! Can't make an omelette etc I suppose! Want to be cleaning this TONIGHT so it'll be whatever I can get, probably this: Bit concerned tbh about harm to any wee beasties as the run off from here ends up on the garden. I wonder id a good scub with some Ecover type washing up liquid and a rinse would do it? Edited June 25, 2019 by Onoff Link to comment Share on other sites More sharing options...
Barney12 Posted June 25, 2019 Share Posted June 25, 2019 I don't think you'll kill too much as long as you dilute it and rinse. You really do need to give it time to dry though. Its forecast to be sunny for the rest of the week so don't panic TBH the stuff sticks like sh*t to a blanket so don't get too worried. As you also know I'm sure its far from a permanent solution. We've got an old industrial shed and it gets a fresh coat ever 18m or so as to replace the roof will be a massive cost. Link to comment Share on other sites More sharing options...
Barney12 Posted June 25, 2019 Share Posted June 25, 2019 P.S. I might be tempted to run some flashband under that last line of tiles and onto the freshly dried Chromopal. Its another bodge but might help. Link to comment Share on other sites More sharing options...
Onoff Posted June 25, 2019 Author Share Posted June 25, 2019 (edited) Well aware I'm throwing good money after bad here... A bit precarious taking this: There is a bit of a fall: The No Nonsense degreaser seems to shift the grime: Daddy's not so little Amish helper: Detailing is bloody awful: Waiting for it to dry: Edited June 25, 2019 by Onoff Link to comment Share on other sites More sharing options...
ProDave Posted June 25, 2019 Share Posted June 25, 2019 Major flaw there. What stops the water running off the 3 ridge tiles from running UNDER the top layer of felt that seems to stop short and not go under those ridge tiles? Link to comment Share on other sites More sharing options...
Onoff Posted June 25, 2019 Author Share Posted June 25, 2019 32 minutes ago, ProDave said: Major flaw there. What stops the water running off the 3 ridge tiles from running UNDER the top layer of felt that seems to stop short and not go under those ridge tiles? I've pushed the tiles up in the pic to show the detail. Link to comment Share on other sites More sharing options...
Onoff Posted June 26, 2019 Author Share Posted June 26, 2019 Couple of hours tonight. Link to comment Share on other sites More sharing options...
Onoff Posted November 5, 2019 Author Share Posted November 5, 2019 (edited) I blame @Visti! ? Totally the wrong time of year to contemplate it but I'm considering (again) doing my dormer roof, or at least half of it, YES, in this weather! I NEED a big project to make a mess and take ages! Be nice for SWMBO to be able to moan about how I took the roof just before Christmas! One half has had £££ worth of Flexacryl etc put on as above and is holding up at the moment. A stain has recently appeared on our bedroom ceiling under the untouched side, no suprises there. Both sides were badly re-felted again as aforementioned. The side that needs doing is the really dangerous side in terms of fall hazards. Looking at it the other day and they definitely laid new felt over old with adhesive only at the edges. I don't think the new felt was even overlapped, just butt jointed judging by the way its separating at the joins. Shrinkage? Ideally I'd pay for a proper scaffold roof to shield the works from the elements but that wont happen. If I do it it'd be with some form of quick to deploy tarpaulin. Im really liking the idea of doing away with the centre "ridge" and just having one big roof area. Even considering an access hatch out of the top. Fibreglass seems the logical way to go but obviously not the weather for it. EPDM maybe...one big piece? Been putting this off for years as to really complicate things I'm still considering externally insulating the roof and then eventually down the front and cheeks of the dormer. Then later the hips either side. I've REALLY got to consider the detailing of this...time for a scale model maybe! Half thinking as an "interim" repair to reroof each half in EPDM to get over the immediate leak issues then later, in better weather rip the lot off and maybe even fibreglass? Even doing EPDM now the fascias and soffit boards need redoing along with new firings to increase the slope angle. Keep thinking of @Barney12's cracking detail of the fibreglass dormer with hidden gutters. Another JFDI job! Edited November 5, 2019 by Onoff Link to comment Share on other sites More sharing options...
Visti Posted November 5, 2019 Share Posted November 5, 2019 I am happy to take full credit Link to comment Share on other sites More sharing options...
Ferdinand Posted November 5, 2019 Share Posted November 5, 2019 New Avatar. Beautiful again. Link to comment Share on other sites More sharing options...
Onoff Posted November 5, 2019 Author Share Posted November 5, 2019 1 hour ago, Ferdinand said: New Avatar. Beautiful again. The scary one was just for Halloween. Link to comment Share on other sites More sharing options...
Onoff Posted June 12, 2020 Author Share Posted June 12, 2020 The saga continues. Not unexpectedly the roof on the left has finally failed and we have a wet patch on our bedroom ceiling. This weekend I need to get up there and do something. If I don't it'll soon be dripping! As regular readers might recall I've been prevaricating over this for years now. Originally (dormer built around 1987/88) the whole square of the dormer was sheeted in 3/4" ply. A layer of sand felt went over this. (I can see this from inside looking along the pitch). Two bits of 4×2 were then nailed about a ridge board at the top and skewed through the first layer of felt/ply at the bottom to make the pitch. Again, visible from inside. This was then covered in string reinforced felt, tiled and battened. Subsequent layer(s) of roofing felt went over this first layer of sand felt at the sides. Gut feel is they stopped just under the tiles. Might have been a second layer of sand felt but I can't tell. At some point just the flat side bits have been over felted again leaving the failed stuff underneath by the looks of things. This has created a lip of "new" felt just under the bottom of the tiles. Below you can see the original tattered felt under the pushed back tile. I've always been loathe to redo just the wings as this edge and the pitch are obvious issues. (Spent a small fortune on the other side of the pitch in acrylic roof repair compound over the years. That side still leaks at the corners / edges as the eaves detail is dire. The side that needs immediate work now is tbh odd. I think when it was last done (just before we purchased) they didn't have enough felt so butted sheets together rather than overlap them. These have now separated at the "joins" to leave wide gaps. Bottom line is it needs doing. Short term itl likely be an expanse of DPM laid up there and weighted with slabs whilst I gather my thoughts. Repeating myself here but I can't help thinking doing away with the central pitch would be a good idea. Tbh I dont want to spend to too much on a permanent solution as I've this mad idea of re roofing should my ship come in! ?. Warm roof, access hatch and solar pv trays up there etc with a central access walkway where the pitch is now. A big sheet of EPDM seems like a quick fix. A little concerned as to amount of crows, sparrow hawks etc who use it up there as a dining table and of their talons ripping it. Likewise, pooling water attracts birds, squirrels etc. Wondering if I should invest in a bfo heavy duty tarpaulin and just rip the lot off and see what I've got? Money no object (it is) and I'd put a scaffold over the top / the whole house. What way to go...the "clean slate" method? Link to comment Share on other sites More sharing options...
ToughButterCup Posted June 12, 2020 Share Posted June 12, 2020 Ugh. My instinct is to suggest KISS. Initially that means spending time on design. So, tarp, weights, thinking cap. BH thread. Ian (Toughest Buttercup in the World - just in case @Russell griffithsreads this) Link to comment Share on other sites More sharing options...
SteamyTea Posted June 12, 2020 Share Posted June 12, 2020 (edited) Sheets of PIR/PU and GRP it. Why much about with thinking. Good place to put some walk on glazing, if only someone had a spare bit the right size. Could work well to hold a tarp down. Edited June 12, 2020 by SteamyTea Link to comment Share on other sites More sharing options...
Randomiser Posted June 12, 2020 Share Posted June 12, 2020 Not sure what the answer is, but my gut feel is that it would be hard to make the roof look cohesive and attractive if you do away with the small pitched section. But maybe I just don't have a good enough imagination. Link to comment Share on other sites More sharing options...
Onoff Posted June 12, 2020 Author Share Posted June 12, 2020 (edited) If I do away with the pitch I'm struggling a little to visualise the resultant small gable ends, how to insulate, board weather it etc. CAD time methinks or maybe a scale model... Whatever I do I'd like to have it so that 23 minutes ago, SteamyTea said: Sheets of PIR/PU and GRP it. Why much about with thinking. Good place to put some walk on glazing, if only someone had a spare bit the right size. Could work well to hold a tarp down. In the back of my mind it's always a @Barney12 esque GRP roof and hidden gutter detail. Not sure I could do such a big area in GRP, on my own and with no experience of it. Isn't there a new "paint" on GRP alternative I've read about? If I do away with the pitch I'm struggling a little to visualise the resultant small gable ends, how to insulate, board weather it etc. CAD time methinks or maybe a scale model... Edited June 12, 2020 by Onoff Link to comment Share on other sites More sharing options...
daiking Posted June 12, 2020 Share Posted June 12, 2020 Link to comment Share on other sites More sharing options...
ToughButterCup Posted June 12, 2020 Share Posted June 12, 2020 Ohhhh Gaauuuud folks. How long is he going to take over this one? Opening a book - Any advance on 10:1 less than 86 pages? 1 Link to comment Share on other sites More sharing options...
Onoff Posted June 12, 2020 Author Share Posted June 12, 2020 16 minutes ago, ToughButterCup said: Ohhhh Gaauuuud folks. How long is he going to take over this one? Opening a book - Any advance on 10:1 less than 86 pages? Longest thread in terms of pages? Surely my crown has been taken by another Sire! However in terms of years taken...1st photo on Flickr is August 31st 2015. Pretty sure there're earlier ones on Photobucket..... 1 Link to comment Share on other sites More sharing options...
SteamyTea Posted June 12, 2020 Share Posted June 12, 2020 Would this work https://www.siliconeforbuilding.com/products/air-water-resistive-barrier-coatings I need a litre of it to try something out, but rather you bought it, then I can send you the things to coat. Will include a SAE. Link to comment Share on other sites More sharing options...
Onoff Posted June 12, 2020 Author Share Posted June 12, 2020 (edited) 37 minutes ago, SteamyTea said: Would this work https://www.siliconeforbuilding.com/products/air-water-resistive-barrier-coatings I need a litre of it to try something out, but rather you bought it, then I can send you the things to coat. Will include a SAE. I'll certainly coat it with something and send it back. Only colour here is brown mind? It was the polyurethane liquid waterproofing systems I was thinking of. Seems you lay a mat down as you would with fibreglass etc. Edited June 12, 2020 by Onoff Link to comment Share on other sites More sharing options...
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