I am decorating inside a weather exposed Yorkshire cottage. Horizontal rain and snow today .. nice view though :-)
The windows are wooden frames and rain is driving thru past the cracked cement on the outside and wetting the plasterboard.
If I remove the cement, would it be a good idea to squeeze some of the exterior mastic stuff (brown) between the frame and the stone wall and then finish off with cement again ?
Mike P
================================== Most mastic fillers specify *dry* conditions so you wouldn't do much good with it in the present conditions. Depending on the gap (at least 1/4" wide to be realistic) you could use expanding foam *sparingly* which needs a little water to cure. You would then need to renew the cement fillet to cover the foam.
The easiest way would be to rake out all the old cracked cement and replace with new, working the new stuff well into the gap and finishing with a triangular weathering finish. A sand / cement mix of 5:1 or 4:1 would be about right.
Cic.
On Thu, 31 Jan 2008 20:54:56 GMT, Cicero head down on the keyboard, banged out this message:
.. xxOn Thu, 31 Jan 2008 20:27:55 +0000, Mike P wrote: .. xx .. xx> I am decorating inside a weather exposed Yorkshire cottage. Horizontal .. xx> rain and snow today .. nice view though :-) .. xx> .. xx> The windows are wooden frames and rain is driving thru past the cracked .. xx> cement on the outside and wetting the plasterboard. .. xx> .. xx> If I remove the cement, would it be a good idea to squeeze some of the .. xx> exterior mastic stuff (brown) between the frame and the stone wall and .. xx> then finish off with cement again ? .. xx> .. xx> Mike P .. xx .. xx================================== .. xxMost mastic fillers specify *dry* conditions so you wouldn't do much good .. xxwith it in the present conditions. Depending on the gap (at least 1/4" .. xxwide to be realistic) you could use expanding foam *sparingly* which needs .. xxa little water to cure. You would then need to renew the cement fillet to .. xxcover the foam. .. xx .. xxThe easiest way would be to rake out all the old cracked cement and .. xxreplace with new, working the new stuff well into the gap and finishing .. xxwith a triangular weathering finish. A sand / cement mix of 5:1 or 4:1 .. xxwould be about right. .. xx .. xxCic.
Thanks for that. I will wait until after the weekend and hope the weather eases before I start on the job
Mike P
I've got a similar problem in a house with a cellar. A small DG window has been fitted as a skylight & leaks like a pig.
I've siliconed around the seal between the DG unit & frame without success. Only source of the leak can be where the frame has been cemented into the hole.
Is waterproof PVA any good in these circs? As an admix to the cement?
Dear Mike Much depends on dimensions as the other post says. If it were mine I would:
rake out the gap batten with polythene and allow it to dry out for a few days (if necessary) dependent on the size and variation of the gap, apply a bead of foam in as much of the void as posssible "rearwards" into the house such as to leave 2" of gap still clear (in the old days we used screwed up newspaper twists for this!) put in a dry pack of sand cement render composed as follows; 3 to 1 (NOT weaker) or less sand and Portland cement with SBR (NOT pva as it an re-emulsify) and SIKA No 1 additive until it is either flush with the finish if that (horrible grey) finish suits or better still, within 12mm of the finish leaving a 12 mm deep void Fill the void with a polysulphide mastic of colour of your choice in accordance with Defect Action Sheet 68 from the BRE Chris
=================================== I would guess that water is simply creeping under the cement fillet (between frame and fillet) particularly if the frame is plastic. If this is the case then any additive is unlikely to improve the situation because there will almost always be some standing water on a skylight. A cement fillet is quite a good seal on a vertical face but where water has a chance to *pool* it will find its way through even the smallest channels.
I would suggest that you use a waterproof tape to cover the suspect areas to see if it improves the situation and if it does so leave it in place until the weather improves and then remove the cement fillet and replace with a mastic which will actually *stick* to the plastic. Strips of 'Flashband' would work provided that you can get the surfaces dry enough to apply it.
Cic.
SBR is the only admix worth considering for this, and it doesn't mix into mortar very well. You're almost better applying it to the surface once the mortar is dry. Is there any flashing?
On Thu, 31 Jan 2008 23:31:30 -0800 (PST), snipped-for-privacy@atics.co.uk head down on the keyboard, banged out this message:
.. xxOn 31 Jan, 20:27, Mike P wrote: .. xx> I am decorating inside a weather exposed Yorkshire cottage. .. xx> Horizontal rain and snow today .. nice view though :-) .. xx>
.. xx> The windows are wooden frames and rain is driving thru past the .. xx> cracked cement on the outside and wetting the plasterboard. .. xx>
.. xx> If I remove the cement, would it be a good idea to squeeze some of the .. xx> exterior mastic stuff (brown) between the frame and the stone wall and .. xx> then finish off with cement again ? .. xx>
.. xx> Mike P .. xx .. xxDear Mike .. xxMuch depends on dimensions as the other post says. .. xxIf it were mine I would: .. xx .. xxrake out the gap .. xxbatten with polythene and allow it to dry out for a few days (if .. xxnecessary) .. xxdependent on the size and variation of the gap, apply a bead of foam .. xxin as much of the void as posssible "rearwards" into the house such as .. xxto leave 2" of gap still clear (in the old days we used screwed up .. xxnewspaper twists for this!) .. xxput in a dry pack of sand cement render composed as follows; 3 to 1 .. xx(NOT weaker) or less sand and Portland cement with SBR (NOT pva as it .. xxan re-emulsify) and SIKA No 1 additive until it is either flush with .. xxthe finish if that (horrible grey) finish suits or better still, .. xxwithin 12mm of the finish leaving a 12 mm deep void .. xxFill the void with a polysulphide mastic of colour of your choice in .. xxaccordance with Defect Action Sheet 68 from the BRE .. xxChris
Thanks .... The angled cemet fillet is just over an inch, so I dont expect a massive void. Looks as though I will be asked to do all the windows (where required) when the weather perks up.
Mike P
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