Fire cement – its uses and limitations

Fire Cement is a ready-to-use putty which is heat resistant up to 1250oc. There are a number of manufacturers and brands and it’s available in different sizes in both black and cream. The cement can be used to seal joints in wood stoves, especially around the area where the flue rises out of the top of the stove. It can also be used to repair firebricks. Fire cement when dry is a non-flexible solid sealant (unfortunately “high temperature” flexible silicone sealants degrade above 300 degree Centigrade which is above the normal operating temperature of your stove). The expansion and contraction of your metal stove as it heats up and cools down will inevitably crack any fire cement around joints on the flue and stove pipe.

Cracks in fire cement, or even where it has fallen out, are only a critical issue if smoke is coming through. Assuming your flue and stove are correctly installed and properly maintained, the negative pressure within the flue will draw smoke and fumes up your chimney, preventing any problems and any smoke coming out. But do remember to have your Carbon Monoxide alarm properly located and test it regularly; it provides an immediate warning of any problems.

It’s a routine and simple job to redo the joints with inexpensive fire cement (typically £2.50 for a small tub). First ensure the area is clean, free from dust and rust. To use, wear a latex glove and apply a liberal amount of cement on one finger. Then work the cement well into the cracked or damaged area. As soon as possible, gently heat dry the repaired surfaces, gradually raising the heat to full operating temperature over 3-4 hours. Apply further cement to any fire cracks that may appear.

Use straight from the tub! We always have stock of fire cement in our showroom.

 

Fire Cement

 

 


 Lime mortar and plaster for fireplaces

As part of our stove installation service and where we are “knocking out”, enlarging or building a fireplace, we can offer the option of having the fire opening rendered in Lime (to be precise that’s a base coat of a lime and hemp mix with a lime plaster finish coat).

Lime is a traditional building material with a number of advantages over modern materials:

– it breathes and lets moisture out so is particularly suitable for Victorian brick buildings and older Cotswold stone buildings which don’t have cavity walls or damp courses.
– any small cracks that appear as a building settles, typically get sealed up naturally as the lime mortar/plaster re-carbonates (Lime does not “dry out” in the way we’re used to with modern materials. It sets through a process of carbonisation as it is exposed to Carbon Dioxide CO2 in the air)
– lime is a softer material than modern cement and plaster which means it will give rather than cracking Cotswold stone
– it is a traditional material free of any chemicals, particularly suitable for older buildings and new environmentally friendly buildings. It is usually required for any Listed building.
– using Lime to render a fireplace takes no longer than using sand and cement

 

There’s one thing to watch out for when choosing to have a fireplace rendered in Lime. Lime takes longer to set through the process of carbonisation than the time sand and cement takes to dry out. So, to minimise the risk of plaster cracking, instead of recommending the stove in a newly rendered fireplace isn’t used for 1 week, we recommend the stove isn’t used for 4 weeks.


 Is the Government going to ban woodburning stoves?

Err, no. Not at all.

We really shouldn’t be surprised anymore at how news headlines often distort facts, but the negative publicity about the really positive things included in the Government’s consultation paper published in May 2018 on its 2018 Clean Air Strategy has certainly been puzzling!!

The full story is here: https://consult.defra.gov.uk/environmental-quality/clean-air-strategy-consultation/ and Chapter 6 is the interesting section on “Domestic burning”

Here’s our summary of the key points:

1. Good news – from 2022 only new efficient, high-performance woodburners can be sold. But there’s no suggestion that existing woodburners installed before 2022 cannot continue to be used. Many of these “Ecodesign 2022” stoves are already available; the difference in performance between an Ecodesign stove and a standard woodburning stove is staggering (need convincing? Come and see one in action at our showroom in Stroud).
2. Good news – suppliers will be stopped from mis-selling firewood that they claim is dry or seasoned when they can’t demonstrate it’s actually ready to burn with a moisture content of 20% or less (the plan is that this won’t apply to “bulk” deliveries of firewood for people to dry/season themselves; it’s mainly targeted at garage forecourts etc selling nets of unseasoned logs. Sound familiar?)
3. Good news – local authorities will get new powers to clamp down on illegal domestic burning eg open fires burning wood in urban areas. Open fires and bonfires are absolutely the biggest source of pollution from wood smoke, not properly used woodburning stoves. Local authorities already have some powers to do this but enforcement is difficult and smoke control zones are out of date as towns/cities have developed
4. Good news – certain types of coal with high levels of sulphur emissions when burnt will be banned
5. Good news – people with woodburning stoves are encouraged to get them serviced and swept regularly

What’s not to like?

The government is inviting anyone who’s interested to comment on their proposals before 14/8/18 (just follow the link above to the consultation document).